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Droppelmann CA, Campos-Melo D, Noches V, McLellan C, Szabla R, Lyons TA, Amzil H, Withers B, Kaplanis B, Sonkar KS, Simon A, Buratti E, Junop M, Kramer JM, Strong MJ. Mitigation of TDP-43 toxic phenotype by an RGNEF fragment in amyotrophic lateral sclerosis models. Brain 2024:awae078. [PMID: 38739752 DOI: 10.1093/brain/awae078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 01/24/2024] [Accepted: 02/08/2024] [Indexed: 05/16/2024] Open
Abstract
Aggregation of the RNA-binding protein TAR DNA binding protein (TDP-43) is a hallmark of TDP-proteinopathies including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). As TDP-43 aggregation and dysregulation are causative of neuronal death, there is a special interest in targeting this protein as a therapeutic approach. Previously, we found that TDP-43 extensively co-aggregated with the dual function protein GEF (guanine exchange factor) and RNA-binding protein rho guanine nucleotide exchange factor (RGNEF) in ALS patients. Here, we show that an N-terminal fragment of RGNEF (NF242) interacts directly with the RNA recognition motifs of TDP-43 competing with RNA and that the IPT/TIG domain of NF242 is essential for this interaction. Genetic expression of NF242 in a fruit fly ALS model overexpressing TDP-43 suppressed the neuropathological phenotype increasing lifespan, abolishing motor defects and preventing neurodegeneration. Intracerebroventricular injections of AAV9/NF242 in a severe TDP-43 murine model (rNLS8) improved lifespan and motor phenotype, and decreased neuroinflammation markers. Our results demonstrate an innovative way to target TDP-43 proteinopathies using a protein fragment with a strong affinity for TDP-43 aggregates and a mechanism that includes competition with RNA sequestration, suggesting a promising therapeutic strategy for TDP-43 proteinopathies such as ALS and FTD.
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Affiliation(s)
- Cristian A Droppelmann
- Molecular Medicine Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Danae Campos-Melo
- Molecular Medicine Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Veronica Noches
- Molecular Medicine Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Crystal McLellan
- Molecular Medicine Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Robert Szabla
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Taylor A Lyons
- Molecular Medicine Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Hind Amzil
- Molecular Medicine Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Benjamin Withers
- Molecular Medicine Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Brianna Kaplanis
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Kirti S Sonkar
- International Centre for Genetic Engineering and Biotechnology (ICGEB), AREA Science Park, 34149 Trieste, Italy
| | - Anne Simon
- Department of Biology, Faculty of Science, Western University, London, Ontario N6A 5B7, Canada
| | - Emanuele Buratti
- International Centre for Genetic Engineering and Biotechnology (ICGEB), AREA Science Park, 34149 Trieste, Italy
| | - Murray Junop
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Jamie M Kramer
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Michael J Strong
- Molecular Medicine Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
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2
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Rots D, Jakub TE, Keung C, Jackson A, Banka S, Pfundt R, de Vries BBA, van Jaarsveld RH, Hopman SMJ, van Binsbergen E, Valenzuela I, Hempel M, Bierhals T, Kortüm F, Lecoquierre F, Goldenberg A, Hertz JM, Andersen CB, Kibæk M, Prijoles EJ, Stevenson RE, Everman DB, Patterson WG, Meng L, Gijavanekar C, De Dios K, Lakhani S, Levy T, Wagner M, Wieczorek D, Benke PJ, Lopez Garcia MS, Perrier R, Sousa SB, Almeida PM, Simões MJ, Isidor B, Deb W, Schmanski AA, Abdul-Rahman O, Philippe C, Bruel AL, Faivre L, Vitobello A, Thauvin C, Smits JJ, Garavelli L, Caraffi SG, Peluso F, Davis-Keppen L, Platt D, Royer E, Leeuwen L, Sinnema M, Stegmann APA, Stumpel CTRM, Tiller GE, Bosch DGM, Potgieter ST, Joss S, Splitt M, Holden S, Prapa M, Foulds N, Douzgou S, Puura K, Waltes R, Chiocchetti AG, Freitag CM, Satterstrom FK, De Rubeis S, Buxbaum J, Gelb BD, Branko A, Kushima I, Howe J, Scherer SW, Arado A, Baldo C, Patat O, Bénédicte D, Lopergolo D, Santorelli FM, Haack TB, Dufke A, Bertrand M, Falb RJ, Rieß A, Krieg P, Spranger S, Bedeschi MF, Iascone M, Josephi-Taylor S, Roscioli T, Buckley MF, Liebelt J, Dagli AI, Aten E, Hurst ACE, Hicks A, Suri M, Aliu E, Naik S, Sidlow R, Coursimault J, Nicolas G, Küpper H, Petit F, Ibrahim V, Top D, Di Cara F, Louie RJ, Stolerman E, Brunner HG, Vissers LELM, Kramer JM, Kleefstra T. The clinical and molecular spectrum of the KDM6B-related neurodevelopmental disorder. Am J Hum Genet 2023; 110:963-978. [PMID: 37196654 PMCID: PMC10257005 DOI: 10.1016/j.ajhg.2023.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 04/24/2023] [Indexed: 05/19/2023] Open
Abstract
De novo variants are a leading cause of neurodevelopmental disorders (NDDs), but because every monogenic NDD is different and usually extremely rare, it remains a major challenge to understand the complete phenotype and genotype spectrum of any morbid gene. According to OMIM, heterozygous variants in KDM6B cause "neurodevelopmental disorder with coarse facies and mild distal skeletal abnormalities." Here, by examining the molecular and clinical spectrum of 85 reported individuals with mostly de novo (likely) pathogenic KDM6B variants, we demonstrate that this description is inaccurate and potentially misleading. Cognitive deficits are seen consistently in all individuals, but the overall phenotype is highly variable. Notably, coarse facies and distal skeletal anomalies, as defined by OMIM, are rare in this expanded cohort while other features are unexpectedly common (e.g., hypotonia, psychosis, etc.). Using 3D protein structure analysis and an innovative dual Drosophila gain-of-function assay, we demonstrated a disruptive effect of 11 missense/in-frame indels located in or near the enzymatic JmJC or Zn-containing domain of KDM6B. Consistent with the role of KDM6B in human cognition, we demonstrated a role for the Drosophila KDM6B ortholog in memory and behavior. Taken together, we accurately define the broad clinical spectrum of the KDM6B-related NDD, introduce an innovative functional testing paradigm for the assessment of KDM6B variants, and demonstrate a conserved role for KDM6B in cognition and behavior. Our study demonstrates the critical importance of international collaboration, sharing of clinical data, and rigorous functional analysis of genetic variants to ensure correct disease diagnosis for rare disorders.
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Affiliation(s)
- Dmitrijs Rots
- Radboudumc, Department of Human Genetics, Nijmegen, the Netherlands
| | - Taryn E Jakub
- Dalhousie University, Department of Biochemistry and Molecular Biology, Faculty of Medicine, Halifax, NS, Canada
| | - Crystal Keung
- Dalhousie University, Department of Biochemistry and Molecular Biology, Faculty of Medicine, Halifax, NS, Canada
| | - Adam Jackson
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Siddharth Banka
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK; Manchester Centre for Genomic Medicine, St. Mary's Hospital, Manchester University NHS Foundation Trust, Health Innovation Manchester, Manchester, UK
| | - Rolph Pfundt
- Radboudumc, Department of Human Genetics, Nijmegen, the Netherlands
| | | | | | - Saskia M J Hopman
- Department of Genetics, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Ellen van Binsbergen
- Department of Genetics, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Irene Valenzuela
- Hospital Universitari Vall D'Hebron, Clinical and Molecular Genetics Unit, Barcelona, Catalonia, Spain
| | - Maja Hempel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tatjana Bierhals
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Fanny Kortüm
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Francois Lecoquierre
- University Rouen Normandie, Inserm U1245 and CHU Rouen, Department of Genetics and Reference Center for Developmental Disorders, 76000 Rouen, France
| | - Alice Goldenberg
- University Rouen Normandie, Inserm U1245 and CHU Rouen, Department of Genetics and Reference Center for Developmental Disorders, 76000 Rouen, France
| | - Jens Michael Hertz
- Odense University Hospital, Department of Clinical Genetics, Odense, Denmark; University of Southern Denmark, Department of Clinical Research, Odense, Denmark
| | | | - Maria Kibæk
- Department of Pediatrics, Odense University Hospital, Odense, Denmark
| | | | | | | | | | - Linyan Meng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Baylor Genetics Laboratories, Houston, TX 77021, USA
| | - Charul Gijavanekar
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Baylor Genetics Laboratories, Houston, TX 77021, USA
| | - Karl De Dios
- Division of Medical Genetics, Dayton Children's Hospital, Dayton, OH, USA
| | - Shenela Lakhani
- Center for Neurogenetics, Weill Cornell Medicine, Brain and Mind Research Institute, New York, NY, USA
| | - Tess Levy
- Center for Neurogenetics, Weill Cornell Medicine, Brain and Mind Research Institute, New York, NY, USA
| | - Matias Wagner
- Institute of Human Genetics, School of Medicine, Technical University Munich, Munich, Germany; Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany; Division of Pediatric Neurology, Department of Pediatrics, Dr. von Hauner Children's Hospital, LMU University Hospital, Munich, Germany
| | - Dagmar Wieczorek
- Institute of Human Genetics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Paul J Benke
- Division of Genetics, Joe DiMaggio Children's Hospital, Hollywood, FL, USA
| | | | - Renee Perrier
- Department of Medical Genetics, Alberta Children's Hospital and Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Sergio B Sousa
- Medical Genetics Unit, Hospital Pediátrico, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - Pedro M Almeida
- Medical Genetics Unit, Hospital Pediátrico, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - Maria José Simões
- CBR Genomics, Cantanhede, Portugal; Genoinseq, Next-Generation Sequencing Unit, Biocant, Cantanhede, Portugal
| | - Bertrand Isidor
- Service de Génétique Médicale, CHU Nantes, 44093 Nantes, France; Université de Nantes, CHU Nantes, CNRS, INSERM, l'Institut du Thorax, 44007 Nantes, France
| | - Wallid Deb
- Service de Génétique Médicale, CHU Nantes, 44093 Nantes, France; Université de Nantes, CHU Nantes, CNRS, INSERM, l'Institut du Thorax, 44007 Nantes, France
| | - Andrew A Schmanski
- Department of Genetic Medicine, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, NE, USA
| | - Omar Abdul-Rahman
- Department of Genetic Medicine, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, NE, USA
| | - Christophe Philippe
- Unité Fonctionnelle Innovation en Diagnostic Génomique des Maladies Rares, Dijon, France; Inserm, UMR1231, Equipe GAD, Bâtiment B3, Université de Bourgogne Franche Comté, Dijon Cedex, France
| | - Ange-Line Bruel
- Unité Fonctionnelle Innovation en Diagnostic Génomique des Maladies Rares, Dijon, France; Inserm, UMR1231, Equipe GAD, Bâtiment B3, Université de Bourgogne Franche Comté, Dijon Cedex, France
| | - Laurence Faivre
- Inserm, UMR1231, Equipe GAD, Bâtiment B3, Université de Bourgogne Franche Comté, Dijon Cedex, France; Centre de Référence Maladies Rares "Anomalies du développement et syndromes malformatifs", Centre de Génétique, FHU-TRANSLAD et Institut GIMI, CHU Dijon Bourgogne, Dijon, France
| | - Antonio Vitobello
- Unité Fonctionnelle Innovation en Diagnostic Génomique des Maladies Rares, Dijon, France; Inserm, UMR1231, Equipe GAD, Bâtiment B3, Université de Bourgogne Franche Comté, Dijon Cedex, France
| | - Christel Thauvin
- Unité Fonctionnelle Innovation en Diagnostic Génomique des Maladies Rares, Dijon, France; Inserm, UMR1231, Equipe GAD, Bâtiment B3, Université de Bourgogne Franche Comté, Dijon Cedex, France; Centre de Référence Déficiences Intellectuelles de Causes Rares, FHU-TRANSLAD, CHU Dijon Bourgogne, Dijon, France
| | - Jeroen J Smits
- Radboudumc, Department of Human Genetics, Nijmegen, the Netherlands
| | - Livia Garavelli
- Medical Genetics Unit, Azienda USL-IRCCS di Reggio Emilia, 42123 Reggio Emilia, Italy
| | - Stefano G Caraffi
- Medical Genetics Unit, Azienda USL-IRCCS di Reggio Emilia, 42123 Reggio Emilia, Italy
| | - Francesca Peluso
- Medical Genetics Unit, Azienda USL-IRCCS di Reggio Emilia, 42123 Reggio Emilia, Italy
| | - Laura Davis-Keppen
- University of South Dakota Sanford School of Medicine and Sanford Children's Hospital, Sioux Falls, SD, USA
| | - Dylan Platt
- University of South Dakota Sanford School of Medicine and Sanford Children's Hospital, Sioux Falls, SD, USA
| | - Erin Royer
- University of South Dakota Sanford School of Medicine and Sanford Children's Hospital, Sioux Falls, SD, USA
| | - Lisette Leeuwen
- University Medical Center Groningen, Department of Genetics, Groningen, the Netherlands
| | - Margje Sinnema
- Maastricht University Medical Center, Department of Clinical Genetics, Maastricht, the Netherlands
| | - Alexander P A Stegmann
- Maastricht University Medical Center, Department of Clinical Genetics, Maastricht, the Netherlands
| | - Constance T R M Stumpel
- Maastricht University Medical Center, Department of Clinical Genetics, Maastricht, the Netherlands; Department of Clinical Genetics and GROW-School for Oncology and Reproduction, Maastricht, the Netherlands
| | - George E Tiller
- Kaiser Permanente, Department of Genetics, Los Angeles, CA, USA
| | | | | | - Shelagh Joss
- West of Scotland Regional Genetics Service, Laboratory Medicine Building, Queen Elizabeth University Hospital, Glasgow, UK
| | - Miranda Splitt
- Northern Genetics Service, Institute of Genetic Medicine, International Centre for Life, Newcastle Upon Tyne NE1 3BZ, UK
| | - Simon Holden
- Department of Clinical Genetics, Cambridge University Hospital NHS Foundation Trust, Cambridge, UK
| | - Matina Prapa
- Department of Clinical Genetics, Cambridge University Hospital NHS Foundation Trust, Cambridge, UK
| | - Nicola Foulds
- Wessex Clinical Genetics Services, University Hospital Southampton NHS Foundation Trust, Southampton SO16 5YA, UK
| | - Sofia Douzgou
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK; Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Kaija Puura
- Department of Child Psychiatry, Tampere University and Tampere University Hospital, Tampere, Finland
| | - Regina Waltes
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Frankfurt, Goethe-Universität, Frankfurt am Main, Germany
| | - Andreas G Chiocchetti
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Frankfurt, Goethe-Universität, Frankfurt am Main, Germany
| | - Christine M Freitag
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Frankfurt, Goethe-Universität, Frankfurt am Main, Germany
| | - F Kyle Satterstrom
- Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Silvia De Rubeis
- Mindich Child Health and Development Institute and Departments of Pediatrics and Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Joseph Buxbaum
- Mindich Child Health and Development Institute and Departments of Pediatrics and Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Bruce D Gelb
- Mindich Child Health and Development Institute and Departments of Pediatrics and Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Aleksic Branko
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Itaru Kushima
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan; Medical Genomics Center, Nagoya University Hospital, Nagoya, Japan
| | - Jennifer Howe
- The Centre for Applied Genomics, Genetics and Genome Biology, The Hospital for Sick Children and University of Toronto, Toronto, ON, Canada
| | - Stephen W Scherer
- The Centre for Applied Genomics, Genetics and Genome Biology, The Hospital for Sick Children and University of Toronto, Toronto, ON, Canada
| | - Alessia Arado
- Laboratory of Human Genetics, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Chiara Baldo
- Laboratory of Human Genetics, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Olivier Patat
- Service de Génétique Médicale, Centre Hospitalier Universitaire de Toulouse, Toulouse, France
| | - Demeer Bénédicte
- Service de Génétique Clinique, Centre de référence maladies rares, CHU d'Amiens-site Sud, Amiens, France
| | - Diego Lopergolo
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy; UOC Neurologia e Malattie Neurometaboliche, Azienda Ospedaliero Universitaria Senese, Policlinico Le Scotte, Viale Bracci, 2, 53100 Siena, Italy; IRCCS Stella Maris Foundation, Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, Pisa, Italy
| | - Filippo M Santorelli
- IRCCS Stella Maris Foundation, Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, Pisa, Italy
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Andreas Dufke
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Miriam Bertrand
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Ruth J Falb
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Angelika Rieß
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Peter Krieg
- Department of Pediatrics, Städtisches Klinikum Karlsruhe, Karlsruhe, Germany
| | | | | | - Maria Iascone
- Laboratory of Medical Genetics, Ospedale Papa Giovanni XXIII, Bergamo, Italy
| | - Sarah Josephi-Taylor
- Department of Clinical Genetics, The Children's Hospital at Westmead, Sydney, NSW, Australia; Discipline of Genomic Medicine, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Tony Roscioli
- Neuroscience Research Australia, University of New South Wales, Sydney, NSW, Australia; New South Wales Health Pathology Randwick Genomics Laboratory, Sydney, NSW, Australia; Centre for Clinical Genetics, Sydney Children's Hospital, Sydney, NSW 2031, Australia; Prince of Wales Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2031, Australia
| | - Michael F Buckley
- New South Wales Health Pathology Randwick Genomics Laboratory, Sydney, NSW, Australia
| | - Jan Liebelt
- South Australian Clinical Genetics Service, Women's and Children's Hospital, Adelaide, SA, Australia
| | - Aditi I Dagli
- Orlando Health Arnold Palmer Hospital for Children, Division of Genetics, Orlando, FL, USA
| | - Emmelien Aten
- Department of Clinical Genetics, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Anna C E Hurst
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alesha Hicks
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mohnish Suri
- Nottingham Clinical Genetics Service, City Hospital Campus, Nottingham, UK
| | - Ermal Aliu
- Department of Pediatrics, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Sunil Naik
- Department of Pediatrics, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Richard Sidlow
- Valley Children's Hospital, Valley Children's Place, Madera, CA 93636, USA
| | - Juliette Coursimault
- University Rouen Normandie, Inserm U1245 and CHU Rouen, Department of Genetics and Reference Center for Developmental Disorders, 76000 Rouen, France
| | - Gaël Nicolas
- University Rouen Normandie, Inserm U1245 and CHU Rouen, Department of Genetics and Reference Center for Developmental Disorders, 76000 Rouen, France
| | - Hanna Küpper
- Neuropediatric Department, University Hospital Tübingen, Tübingen, Germany
| | - Florence Petit
- Centre Hospitalier Universitaire de Lille, Clinique de Génétique Guy Fontaine, Lille, France
| | - Veyan Ibrahim
- Dalhousie University, Department of Biochemistry and Molecular Biology, Faculty of Medicine, Halifax, NS, Canada; Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Deniz Top
- Dalhousie University, Department of Biochemistry and Molecular Biology, Faculty of Medicine, Halifax, NS, Canada; Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Francesca Di Cara
- Department of Microbiology and Immunology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | | | | | - Han G Brunner
- Radboudumc, Department of Human Genetics, Nijmegen, the Netherlands; Maastricht University Medical Center, Department of Clinical Genetics, Maastricht, the Netherlands
| | | | - Jamie M Kramer
- Dalhousie University, Department of Biochemistry and Molecular Biology, Faculty of Medicine, Halifax, NS, Canada.
| | - Tjitske Kleefstra
- Radboudumc, Department of Human Genetics, Nijmegen, the Netherlands; Center for Neuropsychiatry, Vincent van Gogh, Venray, the Netherlands; Department of Clinical Genetics, ErasmusMC, Rotterdam, the Netherlands.
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3
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Kummeling J, Stremmelaar DE, Raun N, Reijnders MRF, Willemsen MH, Ruiterkamp-Versteeg M, Schepens M, Man CCO, Gilissen C, Cho MT, McWalter K, Sinnema M, Wheless JW, Simon MEH, Genetti CA, Casey AM, Terhal PA, van der Smagt JJ, van Gassen KLI, Joset P, Bahr A, Steindl K, Rauch A, Keller E, Raas-Rothschild A, Koolen DA, Agrawal PB, Hoffman TL, Powell-Hamilton NN, Thiffault I, Engleman K, Zhou D, Bodamer O, Hoefele J, Riedhammer KM, Schwaibold EMC, Tasic V, Schubert D, Top D, Pfundt R, Higgs MR, Kramer JM, Kleefstra T. Characterization of SETD1A haploinsufficiency in humans and Drosophila defines a novel neurodevelopmental syndrome. Mol Psychiatry 2021; 26:2013-2024. [PMID: 32346159 DOI: 10.1038/s41380-020-0725-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [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] [Received: 05/03/2019] [Revised: 04/01/2020] [Accepted: 04/01/2020] [Indexed: 12/18/2022]
Abstract
Defects in histone methyltransferases (HMTs) are major contributing factors in neurodevelopmental disorders (NDDs). Heterozygous variants of SETD1A involved in histone H3 lysine 4 (H3K4) methylation were previously identified in individuals with schizophrenia. Here, we define the clinical features of the Mendelian syndrome associated with haploinsufficiency of SETD1A by investigating 15 predominantly pediatric individuals who all have de novo SETD1A variants. These individuals present with a core set of symptoms comprising global developmental delay and/or intellectual disability, subtle facial dysmorphisms, behavioral and psychiatric problems. We examined cellular phenotypes in three patient-derived lymphoblastoid cell lines with three variants: p.Gly535Alafs*12, c.4582-2_4582delAG, and p.Tyr1499Asp. These patient cell lines displayed DNA damage repair defects that were comparable to previously observed RNAi-mediated depletion of SETD1A. This suggested that these variants, including the p.Tyr1499Asp in the catalytic SET domain, behave as loss-of-function (LoF) alleles. Previous studies demonstrated a role for SETD1A in cell cycle control and differentiation. However, individuals with SETD1A variants do not show major structural brain defects or severe microcephaly, suggesting that defective proliferation and differentiation of neural progenitors is unlikely the single underlying cause of the disorder. We show here that the Drosophila melanogaster SETD1A orthologue is required in postmitotic neurons of the fly brain for normal memory, suggesting a role in post development neuronal function. Together, this study defines a neurodevelopmental disorder caused by dominant de novo LoF variants in SETD1A and further supports a role for H3K4 methyltransferases in the regulation of neuronal processes underlying normal cognitive functioning.
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Affiliation(s)
- Joost Kummeling
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Diante E Stremmelaar
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Nicholas Raun
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada.,Department of Physiology and Pharmacology, The University of Western Ontario, London, ON, Canada
| | - Margot R F Reijnders
- Department of Clinical Genetics and School for Oncology & Developmental Biology (GROW), Maastricht University Medical Center, 6229 ER, Maastricht, The Netherlands
| | - Marjolein H Willemsen
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Martina Ruiterkamp-Versteeg
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Marga Schepens
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Calvin C O Man
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Christian Gilissen
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | | | | | - Margje Sinnema
- Department of Clinical Genetics and School for Oncology & Developmental Biology (GROW), Maastricht University Medical Center, 6229 ER, Maastricht, The Netherlands
| | - James W Wheless
- Division of Pediatric Neurology, University of Tennessee Health Science Center, Memphis, TN, USA.,Neuroscience Institute & Le Bonheur Comprehensive Epilepsy Program, Le Bonheur Children's Hospital, Memphis, TN, USA
| | - Marleen E H Simon
- Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Casie A Genetti
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital/Harvard Medical School, Boston, MA, USA.,The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Alicia M Casey
- Division of Pulmonary and Respiratory Diseases, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Paulien A Terhal
- Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Jasper J van der Smagt
- Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Koen L I van Gassen
- Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Pascal Joset
- Institute of Medical Genetics, University of Zurich, Schlieren, 8952, Zurich, Switzerland
| | - Angela Bahr
- Institute of Medical Genetics, University of Zurich, Schlieren, 8952, Zurich, Switzerland
| | - Katharina Steindl
- Institute of Medical Genetics, University of Zurich, Schlieren, 8952, Zurich, Switzerland
| | - Anita Rauch
- Institute of Medical Genetics, University of Zurich, Schlieren, 8952, Zurich, Switzerland
| | - Elmar Keller
- Division of Neuropediatrics, Cantonal Hospital Graubuenden, Chur, Switzerland
| | - Annick Raas-Rothschild
- Institute of Rare Disease, Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
| | - David A Koolen
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Pankaj B Agrawal
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital/Harvard Medical School, Boston, MA, USA.,The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA.,Division of Newborn Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Trevor L Hoffman
- Regional Department of Genetics, Southern California Kaiser Permanente Medical Group, 1188N. Euclid Street, Anaheim, CA, 92801, USA
| | - Nina N Powell-Hamilton
- Division of Medical Genetics, Alfred I. duPont Hospital for Children, Wilmington, DE, 19803, USA.,Department of Pathology and Laboratory Medicine, University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA
| | - Isabelle Thiffault
- Center for Pediatric Genomic Medicine, Children's Mercy Hospital, University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA.,Division of Clinical Genetics, Children's Mercy Hospital, University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA
| | - Kendra Engleman
- Department of Pediatrics, Children's Mercy Hospital, University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA
| | - Dihong Zhou
- Department of Pediatrics, Children's Mercy Hospital, University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA
| | - Olaf Bodamer
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital/Harvard Medical School, Boston, MA, USA
| | - Julia Hoefele
- Institute of Human Genetics, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Korbinian M Riedhammer
- Institute of Human Genetics, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,Department of Nephrology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | | | - Velibor Tasic
- Medical School Skopje, University Children's Hospital, Skopje, North Macedonia
| | - Dirk Schubert
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Deniz Top
- Department of Pediatrics, Dalhousie University, Halifax, NS, Canada
| | - Rolph Pfundt
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Martin R Higgs
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Jamie M Kramer
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada.,Department of Physiology and Pharmacology, The University of Western Ontario, London, ON, Canada
| | - Tjitske Kleefstra
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
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4
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Riahi H, Fenckova M, Goruk KJ, Schenck A, Kramer JM. The epigenetic regulator G9a attenuates stress-induced resistance and metabolic transcriptional programs across different stressors and species. BMC Biol 2021; 19:112. [PMID: 34030685 PMCID: PMC8142638 DOI: 10.1186/s12915-021-01025-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 04/14/2021] [Indexed: 01/07/2023] Open
Abstract
Background Resistance and tolerance are two coexisting defense strategies for fighting infections. Resistance is mediated by signaling pathways that induce transcriptional activation of resistance factors that directly eliminate the pathogen. Tolerance refers to adaptations that limit the health impact of a given pathogen burden, without targeting the infectious agent. The key players governing immune tolerance are largely unknown. In Drosophila, the histone H3 lysine 9 (H3K9) methyltransferase G9a was shown to mediate tolerance to virus infection and oxidative stress (OS), suggesting that abiotic stresses like OS may also evoke tolerance mechanisms. In response to both virus and OS, stress resistance genes were overinduced in Drosophila G9a mutants, suggesting an intact but overactive stress response. We recently demonstrated that G9a promotes tolerance to OS by maintaining metabolic homeostasis and safeguarding energy availability, but it remained unclear if this mechanism also applies to viral infection, or is conserved in other species and stress responses. To address these questions, we analyzed publicly available datasets from Drosophila, mouse, and human in which global gene expression levels were measured in G9a-depleted conditions and controls at different time points upon stress exposure. Results In all investigated datasets, G9a attenuates the transcriptional stress responses that confer resistance against the encountered stressor. Comparative analysis of conserved G9a-dependent stress response genes suggests that G9a is an intimate part of the design principles of stress resistance, buffering the induction of promiscuous stress signaling pathways and stress-specific resistance factors. Importantly, we find stress-dependent downregulation of metabolic genes to also be dependent on G9a across all of the tested datasets. Conclusions These results suggest that G9a sets the balance between activation of resistance genes and maintaining metabolic homeostasis, thereby ensuring optimal organismal performance during exposure to diverse types of stress across different species. We therefore propose G9a as a potentially conserved master regulator underlying the widely important, yet poorly understood, concept of stress tolerance. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01025-0.
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Affiliation(s)
- Human Riahi
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Michaela Fenckova
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Kayla J Goruk
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Annette Schenck
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Jamie M Kramer
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada.
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5
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Abstract
Drosophila melanogaster males reduce courtship behaviour after mating failure. In the lab, such conditioned courtship suppression, aka 'courtship conditioning', serves as a complex learning and memory assay. Interestingly, variations in the courtship conditioning assay can establish different types of memory. Here, we review research investigating the underlying cellular and molecular mechanisms that allow male flies to form memories of previous mating failures.
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Affiliation(s)
- Nicholas Raun
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Spencer Jones
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jamie M Kramer
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
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6
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Nixon KC, Rousseau J, Stone MH, Sarikahya M, Ehresmann S, Mizuno S, Matsumoto N, Miyake N, Baralle D, McKee S, Izumi K, Ritter AL, Heide S, Héron D, Depienne C, Titheradge H, Kramer JM, Campeau PM, Campeau PM. A Syndromic Neurodevelopmental Disorder Caused by Mutations in SMARCD1, a Core SWI/SNF Subunit Needed for Context-Dependent Neuronal Gene Regulation in Flies. Am J Hum Genet 2019; 104:596-610. [PMID: 30879640 DOI: 10.1016/j.ajhg.2019.02.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 01/31/2019] [Indexed: 12/22/2022] Open
Abstract
Mutations in several genes encoding components of the SWI/SNF chromatin remodeling complex cause neurodevelopmental disorders (NDDs). Here, we report on five individuals with mutations in SMARCD1; the individuals present with developmental delay, intellectual disability, hypotonia, feeding difficulties, and small hands and feet. Trio exome sequencing proved the mutations to be de novo in four of the five individuals. Mutations in other SWI/SNF components cause Coffin-Siris syndrome, Nicolaides-Baraitser syndrome, or other syndromic and non-syndromic NDDs. Although the individuals presented here have dysmorphisms and some clinical overlap with these syndromes, they lack their typical facial dysmorphisms. To gain insight into the function of SMARCD1 in neurons, we investigated the Drosophila ortholog Bap60 in postmitotic memory-forming neurons of the adult Drosophila mushroom body (MB). Targeted knockdown of Bap60 in the MB of adult flies causes defects in long-term memory. Mushroom-body-specific transcriptome analysis revealed that Bap60 is required for context-dependent expression of genes involved in neuron function and development in juvenile flies when synaptic connections are actively being formed in response to experience. Taken together, we identify an NDD caused by SMARCD1 mutations and establish a role for the SMARCD1 ortholog Bap60 in the regulation of neurodevelopmental genes during a critical time window of juvenile adult brain development when neuronal circuits that are required for learning and memory are formed.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Philippe M Campeau
- Centre Hospitalier Universitaire Sainte-Justine Research Center, University of Montreal, Montreal, QC H3T 1C5, Canada; Department of Pediatrics, University of Montreal, Montreal, QC H4A 3J1, Canada.
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7
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Chubak MC, Nixon KCJ, Stone MH, Raun N, Rice SL, Sarikahya M, Jones SG, Lyons TA, Jakub TE, Mainland RLM, Knip MJ, Edwards TN, Kramer JM. Individual components of the SWI/SNF chromatin remodelling complex have distinct roles in memory neurons of the Drosophila mushroom body. Dis Model Mech 2019; 12:12/3/dmm037325. [PMID: 30923190 PMCID: PMC6451433 DOI: 10.1242/dmm.037325] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 02/23/2019] [Indexed: 12/13/2022] Open
Abstract
Technology has led to rapid progress in the identification of genes involved in neurodevelopmental disorders such as intellectual disability (ID), but our functional understanding of the causative genes is lagging. Here, we show that the SWI/SNF chromatin remodelling complex is one of the most over-represented cellular components disrupted in ID. We investigated the role of individual subunits of this large protein complex using targeted RNA interference in post-mitotic memory-forming neurons of the Drosophila mushroom body (MB). Knockdown flies were tested for defects in MB morphology, short-term memory and long-term memory. Using this approach, we identified distinct roles for individual subunits of the Drosophila SWI/SNF complex. Bap60, Snr1 and E(y)3 are required for pruning of the MBγ neurons during pupal morphogenesis, while Brm and Osa are required for survival of MBγ axons during ageing. We used the courtship conditioning assay to test the effect of MB-specific SWI/SNF knockdown on short- and long-term memory. Several subunits, including Brm, Bap60, Snr1 and E(y)3, were required in the MB for both short- and long-term memory. In contrast, Osa knockdown only reduced long-term memory. Our results suggest that individual components of the SWI/SNF complex have different roles in the regulation of structural plasticity, survival and functionality of post-mitotic MB neurons. This study highlights the many possible processes that might be disrupted in SWI/SNF-related ID disorders. Our broad phenotypic characterization provides a starting point for understanding SWI/SNF-mediated gene regulatory mechanisms that are important for development and function of post-mitotic neurons. Summary: The SWI/SNF chromatin remodelling complex is the most over-represented protein complex in the intellectual disability. Different components of this complex have distinct roles in development and function of memory-forming neurons in the Drosophila mushroom body.
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Affiliation(s)
- Melissa C Chubak
- Department of Biology, Faculty of Science, Western University, London, ON N6A 5B7, Canada
| | - Kevin C J Nixon
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Max H Stone
- Department of Biology, Faculty of Science, Western University, London, ON N6A 5B7, Canada.,Division of Genetics and Development, Children's Health Research Institute, London, ON N6C 2V5, Canada
| | - Nicholas Raun
- Department of Biology, Faculty of Science, Western University, London, ON N6A 5B7, Canada.,Division of Genetics and Development, Children's Health Research Institute, London, ON N6C 2V5, Canada
| | - Shelby L Rice
- Department of Biology, Faculty of Science, Western University, London, ON N6A 5B7, Canada
| | - Mohammed Sarikahya
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Spencer G Jones
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Taylor A Lyons
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Taryn E Jakub
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Roslyn L M Mainland
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Maria J Knip
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Tara N Edwards
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Jamie M Kramer
- Department of Biology, Faculty of Science, Western University, London, ON N6A 5B7, Canada .,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada.,Division of Genetics and Development, Children's Health Research Institute, London, ON N6C 2V5, Canada
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8
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Castells-Nobau A, Eidhof I, Fenckova M, Brenman-Suttner DB, Scheffer-de Gooyert JM, Christine S, Schellevis RL, van der Laan K, Quentin C, van Ninhuijs L, Hofmann F, Ejsmont R, Fisher SE, Kramer JM, Sigrist SJ, Simon AF, Schenck A. Conserved regulation of neurodevelopmental processes and behavior by FoxP in Drosophila. PLoS One 2019; 14:e0211652. [PMID: 30753188 PMCID: PMC6372147 DOI: 10.1371/journal.pone.0211652] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [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: 01/16/2019] [Accepted: 01/17/2019] [Indexed: 12/30/2022] Open
Abstract
FOXP proteins form a subfamily of evolutionarily conserved transcription factors involved in the development and functioning of several tissues, including the central nervous system. In humans, mutations in FOXP1 and FOXP2 have been implicated in cognitive deficits including intellectual disability and speech disorders. Drosophila exhibits a single ortholog, called FoxP, but due to a lack of characterized mutants, our understanding of the gene remains poor. Here we show that the dimerization property required for mammalian FOXP function is conserved in Drosophila. In flies, FoxP is enriched in the adult brain, showing strong expression in ~1000 neurons of cholinergic, glutamatergic and GABAergic nature. We generate Drosophila loss-of-function mutants and UAS-FoxP transgenic lines for ectopic expression, and use them to characterize FoxP function in the nervous system. At the cellular level, we demonstrate that Drosophila FoxP is required in larvae for synaptic morphogenesis at axonal terminals of the neuromuscular junction and for dendrite development of dorsal multidendritic sensory neurons. In the developing brain, we find that FoxP plays important roles in α-lobe mushroom body formation. Finally, at a behavioral level, we show that Drosophila FoxP is important for locomotion, habituation learning and social space behavior of adult flies. Our work shows that Drosophila FoxP is important for regulating several neurodevelopmental processes and behaviors that are related to human disease or vertebrate disease model phenotypes. This suggests a high degree of functional conservation with vertebrate FOXP orthologues and established flies as a model system for understanding FOXP related pathologies.
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Affiliation(s)
- Anna Castells-Nobau
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Ilse Eidhof
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Michaela Fenckova
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | | | - Jolanda M. Scheffer-de Gooyert
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Sheren Christine
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Rosa L. Schellevis
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Kiran van der Laan
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Christine Quentin
- Genetics, Institute of Biology, Freie Universität Berlin, Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Lisa van Ninhuijs
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Falko Hofmann
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Radoslaw Ejsmont
- Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), Dresden, Germany
| | - Simon E. Fisher
- Language and Genetics Department, Max Planck Institute of Psycholinguistics, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
| | - Jamie M. Kramer
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Stephan J. Sigrist
- Genetics, Institute of Biology, Freie Universität Berlin, Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Anne F. Simon
- Department of Biology, Faculty of Science, Western University, London, Ontario, Canada
| | - Annette Schenck
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
- * E-mail:
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9
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Abstract
Burning mouth syndrome (BMS) is a debilitating condition that has a striking female predilection. Although the oral mucosa is normal in appearance, patients with BMS experience oral burning that most commonly localizes to the lips and tongue. BMS is a diagnosis of exclusion, and all underlying pathoses associated with allodynia must be ruled out prior to rendering the diagnosis. The etiopathogenesis of BMS remains poorly understood, and thus patient management is challenging. Data indicate that oral and systemic factors both contribute to the development and persistence of the condition. Of particular interest, emerging work identifies structural and functional deficits within the nervous system that may lead to a more mechanistic understanding of BMS pathology. In addition, several novel findings suggest that circadian rhythm dysfunction may be a previously unappreciated yet clinically significant driver of disease. Circadian rhythm controls pain perception, mood, and sleep and plays a key role in the regulation of the hypothalamic-pituitary-adrenal axis. Since these are altered in patients with BMS, this may be reflective of underlying circadian dysfunction. While evidence-based treatment strategies for BMS are lacking, current treatment approaches consist of local and systemic medications, such as clonazepam, alpha lipoic acid, capsaicin, low-level laser therapy, gabapentin, and amitriptylin. In addition, the use of cognitive behavioral therapy is reported. This review provides an overview of the recent literature related to the etiology and treatment of BMS and identifies current challenges facing researchers and clinicians alike.
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Affiliation(s)
- A Ritchie
- 1 Department of Oral Pathology, Medicine and Radiology, School of Dentistry, Indiana University, Indianapolis, IN, USA
| | - J M Kramer
- 2 Department of Oral Biology, School of Dental Medicine, State University of New York at Buffalo, Buffalo, NY, USA.,3 Department of Oral Diagnostic Sciences, School of Dental Medicine, State University of New York at Buffalo, Buffalo, NY, USA
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10
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Farhan SMK, Nixon KCJ, Everest M, Edwards TN, Long S, Segal D, Knip MJ, Arts HH, Chakrabarti R, Wang J, Robinson JF, Lee D, Mirsattari SM, Rupar CA, Siu VM, Poulter MO, Hegele RA, Kramer JM. Identification of a novel synaptic protein, TMTC3, involved in periventricular nodular heterotopia with intellectual disability and epilepsy. Hum Mol Genet 2018; 26:4278-4289. [PMID: 28973161 PMCID: PMC5886076 DOI: 10.1093/hmg/ddx316] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [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] [Received: 03/29/2017] [Accepted: 08/08/2017] [Indexed: 12/30/2022] Open
Abstract
Defects in neuronal migration cause brain malformations, which are associated with intellectual disability (ID) and epilepsy. Using exome sequencing, we identified compound heterozygous variants (p.Arg71His and p. Leu729ThrfsTer6) in TMTC3, encoding transmembrane and tetratricopeptide repeat containing 3, in four siblings with nocturnal seizures and ID. Three of the four siblings have periventricular nodular heterotopia (PVNH), a common brain malformation caused by failure of neurons to migrate from the ventricular zone to the cortex. Expression analysis using patient-derived cells confirmed reduced TMTC3 transcript levels and loss of the TMTC3 protein compared to parental and control cells. As TMTC3 function is currently unexplored in the brain, we gathered support for a neurobiological role for TMTC3 by generating flies with post-mitotic neuron-specific knockdown of the highly conserved Drosophila melanogaster TMTC3 ortholog, CG4050/tmtc3. Neuron-specific knockdown of tmtc3 in flies resulted in increased susceptibility to induced seizures. Importantly, this phenotype was rescued by neuron-specific expression of human TMTC3, suggesting a role for TMTC3 in seizure biology. In addition, we observed co-localization of TMTC3 in the rat brain with vesicular GABA transporter (VGAT), a presynaptic marker for inhibitory synapses. TMTC3 is localized at VGAT positive pre-synaptic terminals and boutons in the rat hypothalamus and piriform cortex, suggesting a role for TMTC3 in the regulation of GABAergic inhibitory synapses. TMTC3 did not co-localize with Vglut2, a presynaptic marker for excitatory neurons. Our data identified TMTC3 as a synaptic protein that is involved in PVNH with ID and epilepsy, in addition to its previously described association with cobblestone lissencephaly.
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Affiliation(s)
- Sali M K Farhan
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7.,Department of Biochemistry
| | - Kevin C J Nixon
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Michelle Everest
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Tara N Edwards
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Shirley Long
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Dmitri Segal
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Maria J Knip
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Heleen H Arts
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7.,Division of Genetics and Development, Children's Health Research Institute, London, ON, Canada, N6A 5W9.,Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre Nijmegen, The Netherlands
| | - Rana Chakrabarti
- Division of Genetics and Development, Children's Health Research Institute, London, ON, Canada, N6A 5W9.,Department of Pediatrics
| | - Jian Wang
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7
| | - John F Robinson
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7
| | | | - Seyed M Mirsattari
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1.,Departments of Clinical Neurological Sciences, Medical Biophysics, Medical Imaging and Psychology
| | - C Anthony Rupar
- Department of Biochemistry.,Division of Genetics and Development, Children's Health Research Institute, London, ON, Canada, N6A 5W9.,Department of Pediatrics.,Department of Pathology and Laboratory Medicine, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Victoria M Siu
- Department of Biochemistry.,Division of Genetics and Development, Children's Health Research Institute, London, ON, Canada, N6A 5W9.,Department of Pediatrics
| | | | - Michael O Poulter
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Robert A Hegele
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7.,Department of Biochemistry
| | - Jamie M Kramer
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1.,Division of Genetics and Development, Children's Health Research Institute, London, ON, Canada, N6A 5W9.,Department of Biology, Faculty of Science, Western University, London, ON, Canada, N6A 5B7
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Kramer JM, Hwang IT, Levin M, Acevedo-García D, Rosenfeld L. Identifying environmental barriers to participation: Usability of a health-literacy informed problem-identification approach for parents of young children with developmental disabilities. Child Care Health Dev 2018; 44:249-259. [PMID: 29214658 DOI: 10.1111/cch.12542] [Citation(s) in RCA: 4] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 09/19/2017] [Accepted: 11/04/2017] [Indexed: 11/29/2022]
Abstract
BACKGROUND Parents of very young children recently diagnosed with developmental disabilities (DD) need to identify environmental barriers to their children's participation and adopt an adaptive orientation to solving these problems. Given the health service disparities for diverse families, parents may benefit from easy to use problem-identification approaches that address environmental barriers stemming from community and policy contexts. This feasibility study evaluated the usability of a health literacy-informed, structured, environment-focused problem-identification approach for parents of young children with DD. METHODS We used purposeful, convenience sampling to enrol 9 mothers of children ages 1-3 with DD (4 racial/ethnic minorities, 3 high school education, 4 annual household income <$20,000). We developed a structured problem-identification approach guided by a social ecological model featuring home, community, and policy contexts. The approach was applied to 3 short stories during a narrative elicitation interview. Two researchers independently coded parent responses for the type of barrier and solution identified with and without the approach. RESULTS Parents identified 121 environmental barriers without the approach. When using the approach and prompted to consider home, community, and policy barriers, parents identified an additional 222 environmental barriers; the greatest number of barriers were aligned with International Classification of Functioning, Disability, and Health-Children and Youth environment Chapter 5 "Services, systems, and policies." Using the approach, parents with a postgraduate education and annual household income >$80,000 identified the most environmental barriers, and parents reporting the lowest annual household incomes identified the fewest environmental barriers. When parents attributed participation challenges to an environmental barrier, ~57% of solutions required parents to interact with individuals at the community or policy level. CONCLUSIONS This study suggests that parents with a range of background characteristics can use a structured, environment-focused problem-identification approach. With the approach, parents are more likely to attribute participation challenges to environmental barriers and adopt a problem-solving orientation focused on changes to the community and policy context.
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Affiliation(s)
- J M Kramer
- Department of Occupational Therapy, Boston University, Boston, MA, USA
| | - I T Hwang
- PhD Program in Rehabilitation Sciences, Boston University, Boston, MA, USA
| | - M Levin
- Department of Occupational Therapy, Boston University, Boston, MA, USA
| | - D Acevedo-García
- Institute for Child, Youth and Family Policy, The Heller School for Social Policy and Management, Brandeis University, Waltham, MA, USA
| | - L Rosenfeld
- Institute for Child, Youth and Family Policy, The Heller School for Social Policy and Management, Brandeis University, Waltham, MA, USA
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Mainland RL, Lyons TA, Ruth MM, Kramer JM. Optimal RNA isolation method and primer design to detect gene knockdown by qPCR when validating Drosophila transgenic RNAi lines. BMC Res Notes 2017; 10:647. [PMID: 29187229 PMCID: PMC5707822 DOI: 10.1186/s13104-017-2959-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 11/21/2017] [Indexed: 01/21/2023] Open
Abstract
Objective RNA interference is employed extensively in Drosophila research to study gene function within a specific cell-type or tissue. Thousands of transgenic Drosophila lines have been generated to express double stranded RNA for gene knockdown; however, no standardized method exists for quantifying their knockdown efficiency. Since antibodies are not available for many proteins, quantitative real-time PCR is often used. Here, we explore how primer design and RNA isolation method can influence detection of gene knockdown using qPCR. Results We tested differences in detected gene knockdown efficiency when using purified polyadenylated mRNA or total RNA as templates for cDNA synthesis. We also tested two different primer locations for each gene: one to amplify a region 5′ of the RNAi cut site, and one to amplify a region 3′ of the cut site. Consistently, the strongest gene knockdown was detected when qPCR was performed using 5′ primer sets in combination with mRNA-derived cDNA. Our results indicate that detection of undegraded mRNA cleavage fragments can result in underestimation of true knockdown efficiency for a RNAi construct. Purification of polyadenylated mRNA, combined with primers designed to amplify the non-polyadenylated 5′ mRNA cleavage fragment can avoid this problem. Electronic supplementary material The online version of this article (10.1186/s13104-017-2959-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Roslyn L Mainland
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, 1151 Richmond St., London, ON, N6A 5C1, Canada
| | - Taylor A Lyons
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, 1151 Richmond St., London, ON, N6A 5C1, Canada
| | - Mike M Ruth
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, 1151 Richmond St., London, ON, N6A 5C1, Canada
| | - Jamie M Kramer
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, 1151 Richmond St., London, ON, N6A 5C1, Canada. .,Department of Biology, Faculty of Science, Western University, London, ON, Canada. .,Division of Genetics and Development, Children's Health Research Institute, London, ON, Canada.
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Koemans TS, Kleefstra T, Chubak MC, Stone MH, Reijnders MRF, de Munnik S, Willemsen MH, Fenckova M, Stumpel CTRM, Bok LA, Sifuentes Saenz M, Byerly KA, Baughn LB, Stegmann APA, Pfundt R, Zhou H, van Bokhoven H, Schenck A, Kramer JM. Functional convergence of histone methyltransferases EHMT1 and KMT2C involved in intellectual disability and autism spectrum disorder. PLoS Genet 2017; 13:e1006864. [PMID: 29069077 PMCID: PMC5656305 DOI: 10.1371/journal.pgen.1006864] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [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: 02/02/2017] [Accepted: 06/10/2017] [Indexed: 11/18/2022] Open
Abstract
Kleefstra syndrome, caused by haploinsufficiency of euchromatin histone methyltransferase 1 (EHMT1), is characterized by intellectual disability (ID), autism spectrum disorder (ASD), characteristic facial dysmorphisms, and other variable clinical features. In addition to EHMT1 mutations, de novo variants were reported in four additional genes (MBD5, SMARCB1, NR1I3, and KMT2C), in single individuals with clinical characteristics overlapping Kleefstra syndrome. Here, we present a novel cohort of five patients with de novo loss of function mutations affecting the histone methyltransferase KMT2C. Our clinical data delineates the KMT2C phenotypic spectrum and reinforces the phenotypic overlap with Kleefstra syndrome and other related ID disorders. To elucidate the common molecular basis of the neuropathology associated with mutations in KMT2C and EHMT1, we characterized the role of the Drosophila KMT2C ortholog, trithorax related (trr), in the nervous system. Similar to the Drosophila EHMT1 ortholog, G9a, trr is required in the mushroom body for short term memory. Trr ChIP-seq identified 3371 binding sites, mainly in the promoter of genes involved in neuronal processes. Transcriptional profiling of pan-neuronal trr knockdown and G9a null mutant fly heads identified 613 and 1123 misregulated genes, respectively. These gene sets show a significant overlap and are associated with nearly identical gene ontology enrichments. The majority of the observed biological convergence is derived from predicted indirect target genes. However, trr and G9a also have common direct targets, including the Drosophila ortholog of Arc (Arc1), a key regulator of synaptic plasticity. Our data highlight the clinical and molecular convergence between the KMT2 and EHMT protein families, which may contribute to a molecular network underlying a larger group of ID/ASD-related disorders. Neurodevelopmental disorders (NDDs) like intellectual disability (ID) and autism spectrum disorder (ASD) present an enormous challenge to affected individuals, their families, and society. Understanding the mechanisms underlying NDDs may lead to the development of targeted therapeutics, but this is complicated by the great clinical and genetic heterogeneity seen in patients. Mutations in hundreds of genes have been implicated in NDDs, giving rise to diverse clinical presentations. However, evidence suggests that many of these genes lie in common biological pathways, and mutations in genes that are involved in similar biological functions give rise to more similar clinical phenotypes. Here, we define a novel ID disorder with comorbid ASD (ID/ASD) caused by mutations in KMT2C. This disorder is defined by clinical features that overlap with a group of other disorders, including Kleefstra syndrome, which is caused by EHMT1 mutations. In the fruit fly, we show that the KMT2 and EHMT protein families regulate a highly converging set of biological processes. Both EHMT1 and KMT2C encode histone methyltransferases, which regulate gene transcription by modifying chromatin structure. Further understanding of the common gene regulatory networks associated with this group of ID- and ASD-related disorders may lead to the identification of novel therapeutic targets.
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Affiliation(s)
- Tom S. Koemans
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Radboud Institute of Molecular Life Sciences, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Tjitske Kleefstra
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Melissa C. Chubak
- Department of Biology, Faculty of Science, Western University, London, Ontario, Canada
| | - Max H. Stone
- Department of Biology, Faculty of Science, Western University, London, Ontario, Canada
- Division of Genetics and Development, Children’s Health Research Institute, London, Ontario, Canada
| | - Margot R. F. Reijnders
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Sonja de Munnik
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Marjolein H. Willemsen
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Michaela Fenckova
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Connie T. R. M. Stumpel
- Department of Clinical Genetics and School for Oncology & Developmental Biology (GROW), Maastricht University Medical Center, Maastricht, the Netherlands
| | - Levinus A. Bok
- Department of Pediatrics, Máxima Medical Centre, Veldhoven, The Netherlands
| | | | - Kyna A. Byerly
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Linda B. Baughn
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Alexander P. A. Stegmann
- Department of Clinical Genetics and School for Oncology & Developmental Biology (GROW), Maastricht University Medical Center, Maastricht, the Netherlands
| | - Rolph Pfundt
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Huiqing Zhou
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Radboud Institute of Molecular Life Sciences, Nijmegen, The Netherlands
- Department of Molecular Developmental Biology, Radboud University, Nijmegen, The Netherlands
| | - Hans van Bokhoven
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Annette Schenck
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
- * E-mail: (AS); (JMK)
| | - Jamie M. Kramer
- Department of Biology, Faculty of Science, Western University, London, Ontario, Canada
- Division of Genetics and Development, Children’s Health Research Institute, London, Ontario, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
- * E-mail: (AS); (JMK)
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Koemans TS, Oppitz C, Donders RAT, van Bokhoven H, Schenck A, Keleman K, Kramer JM. Drosophila Courtship Conditioning As a Measure of Learning and Memory. J Vis Exp 2017. [PMID: 28605393 PMCID: PMC5608251 DOI: 10.3791/55808] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [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: 01/09/2023] Open
Abstract
Many insights into the molecular mechanisms underlying learning and memory have been elucidated through the use of simple behavioral assays in model organisms such as the fruit fly, Drosophila melanogaster. Drosophila is useful for understanding the basic neurobiology underlying cognitive deficits resulting from mutations in genes associated with human cognitive disorders, such as intellectual disability (ID) and autism. This work describes a methodology for testing learning and memory using a classic paradigm in Drosophila known as courtship conditioning. Male flies court females using a distinct pattern of easily recognizable behaviors. Premated females are not receptive to mating and will reject the male's copulation attempts. In response to this rejection, male flies reduce their courtship behavior. This learned reduction in courtship behavior is measured over time, serving as an indicator of learning and memory. The basic numerical output of this assay is the courtship index (CI), which is defined as the percentage of time that a male spends courting during a 10 min interval. The learning index (LI) is the relative reduction of CI in flies that have been exposed to a premated female compared to naïve flies with no previous social encounters. For the statistical comparison of LIs between genotypes, a randomization test with bootstrapping is used. To illustrate how the assay can be used to address the role of a gene relating to learning and memory, the pan-neuronal knockdown of Dihydroxyacetone phosphate acyltransferase (Dhap-at) was characterized here. The human ortholog of Dhap-at, glyceronephosphate O-acyltransferase (GNPT), is involved in rhizomelic chondrodysplasia punctata type 2, an autosomal-recessive syndrome characterized by severe ID. Using the courtship conditioning assay, it was determined that Dhap-at is required for long-term memory, but not for short-term memory. This result serves as a basis for further investigation of the underlying molecular mechanisms.
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Affiliation(s)
- Tom S Koemans
- Department of Human Genetics, Radboud University Medical Center; Radboud Institute of Molecular Life Sciences, Radboud University; Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Radboud University
| | | | | | - Hans van Bokhoven
- Department of Human Genetics, Radboud University Medical Center; Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Radboud University
| | - Annette Schenck
- Department of Human Genetics, Radboud University Medical Center; Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Radboud University
| | | | - Jamie M Kramer
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University; Department of Biology, Faculty of Science, Western University;
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15
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Dubos A, Castells-Nobau A, Meziane H, Oortveld MAW, Houbaert X, Iacono G, Martin C, Mittelhaeuser C, Lalanne V, Kramer JM, Bhukel A, Quentin C, Slabbert J, Verstreken P, Sigrist SJ, Messaddeq N, Birling MC, Selloum M, Stunnenberg HG, Humeau Y, Schenck A, Herault Y. Conditional depletion of intellectual disability and Parkinsonism candidate gene ATP6AP2 in fly and mouse induces cognitive impairment and neurodegeneration. Hum Mol Genet 2015; 24:6736-55. [PMID: 26376863 PMCID: PMC4634377 DOI: 10.1093/hmg/ddv380] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [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: 04/14/2015] [Accepted: 09/11/2015] [Indexed: 12/20/2022] Open
Abstract
ATP6AP2, an essential accessory component of the vacuolar H+ ATPase (V-ATPase), has been associated with intellectual disability (ID) and Parkinsonism. ATP6AP2 has been implicated in several signalling pathways; however, little is known regarding its role in the nervous system. To decipher its function in behaviour and cognition, we generated and characterized conditional knockdowns of ATP6AP2 in the nervous system of Drosophila and mouse models. In Drosophila, ATP6AP2 knockdown induced defective phototaxis and vacuolated photoreceptor neurons and pigment cells when depleted in eyes and altered short- and long-term memory when depleted in the mushroom body. In mouse, conditional Atp6ap2 deletion in glutamatergic neurons (Atp6ap2Camk2aCre/0 mice) caused increased spontaneous locomotor activity and altered fear memory. Both Drosophila ATP6AP2 knockdown and Atp6ap2Camk2aCre/0 mice presented with presynaptic transmission defects, and with an abnormal number and morphology of synapses. In addition, Atp6ap2Camk2aCre/0 mice showed autophagy defects that led to axonal and neuronal degeneration in the cortex and hippocampus. Surprisingly, axon myelination was affected in our mutant mice, and axonal transport alterations were observed in Drosophila. In accordance with the identified phenotypes across species, genome-wide transcriptome profiling of Atp6ap2Camk2aCre/0 mouse hippocampi revealed dysregulation of genes involved in myelination, action potential, membrane-bound vesicles and motor behaviour. In summary, ATP6AP2 disruption in mouse and fly leads to cognitive impairment and neurodegeneration, mimicking aspects of the neuropathology associated with ATP6AP2 mutations in humans. Our results identify ATP6AP2 as an essential gene for the nervous system.
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Affiliation(s)
- Aline Dubos
- Institut Clinique de la Souris, PHENOMIN, GIE CERBM, 1 rue Laurent Fries, 67404 Illkirch, France, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France, Centre National de la Recherche Scientifique, UMR7104, Illkirch, France, Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France and Université de Strasbourg, Illkirch, France
| | - Anna Castells-Nobau
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Hamid Meziane
- Institut Clinique de la Souris, PHENOMIN, GIE CERBM, 1 rue Laurent Fries, 67404 Illkirch, France
| | - Merel A W Oortveld
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Xander Houbaert
- Team Synapse in Cognition, Institut Interdisciplinaire de NeuroScience, Centre National de la Recherche Scientifique CNRS UMR5297, Université de Bordeaux, Bordeaux, France
| | - Giovanni Iacono
- Department of Molecular Biology, Radboud Institute for Molecular Life Sciences, Radboud University, Nijmegen, The Netherlands
| | - Christelle Martin
- Team Synapse in Cognition, Institut Interdisciplinaire de NeuroScience, Centre National de la Recherche Scientifique CNRS UMR5297, Université de Bordeaux, Bordeaux, France
| | - Christophe Mittelhaeuser
- Institut Clinique de la Souris, PHENOMIN, GIE CERBM, 1 rue Laurent Fries, 67404 Illkirch, France
| | - Valérie Lalanne
- Institut Clinique de la Souris, PHENOMIN, GIE CERBM, 1 rue Laurent Fries, 67404 Illkirch, France
| | - Jamie M Kramer
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Anuradha Bhukel
- Genetics, Institute of Biology, Freie Universität Berlin, Berlin, Germany
| | - Christine Quentin
- Genetics, Institute of Biology, Freie Universität Berlin, Berlin, Germany, NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Jan Slabbert
- VIB, Center for the Biology of Disease, Leuven, Belgium, KU Leuven, Center for Human Genetics and Leuven Institute for Neuroscience and Disease (LIND), Leuven, Belgium
| | - Patrik Verstreken
- VIB, Center for the Biology of Disease, Leuven, Belgium, KU Leuven, Center for Human Genetics and Leuven Institute for Neuroscience and Disease (LIND), Leuven, Belgium
| | - Stefan J Sigrist
- Genetics, Institute of Biology, Freie Universität Berlin, Berlin, Germany, NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Nadia Messaddeq
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France, Centre National de la Recherche Scientifique, UMR7104, Illkirch, France, Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France and Université de Strasbourg, Illkirch, France
| | - Marie-Christine Birling
- Institut Clinique de la Souris, PHENOMIN, GIE CERBM, 1 rue Laurent Fries, 67404 Illkirch, France
| | - Mohammed Selloum
- Institut Clinique de la Souris, PHENOMIN, GIE CERBM, 1 rue Laurent Fries, 67404 Illkirch, France
| | - Henk G Stunnenberg
- Department of Molecular Biology, Radboud Institute for Molecular Life Sciences, Radboud University, Nijmegen, The Netherlands
| | - Yann Humeau
- Team Synapse in Cognition, Institut Interdisciplinaire de NeuroScience, Centre National de la Recherche Scientifique CNRS UMR5297, Université de Bordeaux, Bordeaux, France
| | - Annette Schenck
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands,
| | - Yann Herault
- Institut Clinique de la Souris, PHENOMIN, GIE CERBM, 1 rue Laurent Fries, 67404 Illkirch, France, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France, Centre National de la Recherche Scientifique, UMR7104, Illkirch, France, Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France and Université de Strasbourg, Illkirch, France
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Kramer JM. Epigenetic regulation of memory: implications in human cognitive disorders. Biomol Concepts 2015; 4:1-12. [PMID: 25436561 DOI: 10.1515/bmc-2012-0026] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 09/13/2012] [Indexed: 11/15/2022] Open
Abstract
Epigenetic modification of chromatin structure is an important mechanism in the regulation of gene expression. Recent studies have shown that dynamic regulation of chromatin structure occurs in response to neuronal stimulation associated with learning and memory. Learning-induced chromatin modifications include DNA methylation, histone acetylation, histone phosphorylation and histone methylation. Studies in animal models have used genetic and pharmacological methods to manipulate the epigenetic machinery in the brain during learning and memory formation. In general, these studies suggest that epigenetic regulation of chromatin structure is essential for long term memory (LTM) consolidation, which is known to require new gene transcription. Analysis of animal models has also implicated epigenetic mechanisms in impaired cognition associated with aging, neurodegenerative disease, and intellectual disability (ID). Recently, it has been shown that a subset of ID disorders and autism are caused by disruption of specific chromatin modification complexes that are involved in nuclear hormone receptor mediated transcriptional regulation. This review provides an overview of chromatin modifications that are implicated in learning and memory and discusses the role of chromatin modifying proteins in learning-induced transcriptional regulation and human cognitive disorders.
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Gregor A, Kramer JM, van der Voet M, Schanze I, Uebe S, Donders R, Reis A, Schenck A, Zweier C. Altered GPM6A/M6 dosage impairs cognition and causes phenotypes responsive to cholesterol in human and Drosophila. Hum Mutat 2015; 35:1495-505. [PMID: 25224183 DOI: 10.1002/humu.22697] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 09/05/2014] [Indexed: 12/28/2022]
Abstract
Glycoprotein M6A (GPM6A) is a neuronal transmembrane protein of the PLP/DM20 (proteolipid protein) family that associates with cholesterol-rich lipid rafts and promotes filopodia formation. We identified a de novo duplication of the GPM6A gene in a patient with learning disability and behavioral anomalies. Expression analysis in blood lymphocytes showed increased GPM6A levels. An increase of patient-derived lymphoblastoid cells carrying membrane protrusions supports a functional effect of this duplication. To study the consequences of GPM6A dosage alterations in an intact nervous system, we employed Drosophila melanogaster as a model organism. We found that knockdown of Drosophila M6, the sole member of the PLP family in flies, in the wing, and whole organism causes malformation and lethality, respectively. These phenotypes as well as the protrusions of patient-derived lymphoblastoid cells with increased GPM6A levels can be alleviated by cholesterol supplementation. Notably, overexpression as well as loss of M6 in neurons specifically compromises long-term memory in the courtship conditioning paradigm. Our findings thus indicate a critical role of correct GPM6A/M6 levels for cognitive function and support a role of the GPM6A duplication for the patient's phenotype. Together with other recent findings, this study highlights compromised cholesterol homeostasis as a recurrent feature in cognitive phenotypes.
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Affiliation(s)
- Anne Gregor
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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18
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Abstract
The euchromatin histone methyltransferases (EHMTs) are an evolutionarily conserved protein family that are known for their ability to dimethylate histone 3 at lysine 9 in euchromatic regions of the genome. In mammals there are two EHMT proteins, G9a, encoded by EHMT2, and GLP, encoded by EHMT1. EHMTs have diverse roles in the differentiation of different tissues and cell types and are involved in adult-specific processes like memory, drug addiction, and immune response. This review discusses recent findings from rodent and Drosophila models that are beginning to reveal the broad biological role and complex mechanistic functioning of EHMT proteins.
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Affiliation(s)
- Jamie M Kramer
- Department of Physiology and Pharmacology, Department of Biology, Western University, London, Ontario, Canada.,Department of Physiology and Pharmacology, Department of Biology, Western University, London, Ontario, Canada
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Merkling SH, Bronkhorst AW, Kramer JM, Overheul GJ, Schenck A, Van Rij RP. The epigenetic regulator G9a mediates tolerance to RNA virus infection in Drosophila. PLoS Pathog 2015; 11:e1004692. [PMID: 25880195 PMCID: PMC4399909 DOI: 10.1371/journal.ppat.1004692] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 01/21/2015] [Indexed: 01/01/2023] Open
Abstract
Little is known about the tolerance mechanisms that reduce the negative effects of microbial infection on host fitness. Here, we demonstrate that the histone H3 lysine 9 methyltransferase G9a regulates tolerance to virus infection by shaping the response of the evolutionary conserved Jak-Stat pathway in Drosophila. G9a-deficient mutants are more sensitive to RNA virus infection and succumb faster to infection than wild-type controls, which was associated with strongly increased Jak-Stat dependent responses, but not with major differences in viral load. Genetic experiments indicate that hyperactivated Jak-Stat responses are associated with early lethality in virus-infected flies. Our results identify an essential epigenetic mechanism underlying tolerance to virus infection. Multicellular organisms deploy various strategies to fight microbial infections. Invading pathogens may be eradicated directly by antimicrobial effectors of the immune system. Another strategy consists of increasing the tolerance of the host to infection, for example, by limiting the adverse effects of the immune response. The molecular mechanisms underlying this novel concept remain largely uncharacterized. Here, we demonstrate that the epigenetic regulator G9a mediates tolerance to virus infection in Drosophila. We found that G9a-deficient flies succumb faster than control flies to infection with RNA viruses, but that the viral burden did not significantly differ. Unexpectedly, mutant flies express higher levels of genes that are regulated by the Jak-Stat signaling pathway, which in other studies was found to be important for antiviral defense. Exploiting the genetic toolbox in Drosophila, we demonstrate that Jak-Stat hyperactivation induces early mortality after virus infection. Precise control of immune pathways is essential to ensure efficient immunity, while preventing damage due to excessive immune responses. Our results indicate that G9a, an epigenetic modifier, dampens Jak-Stat responses to prevent immunopathology. Therefore, we propose epigenetic regulation of immunity as a new paradigm for disease tolerance.
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Affiliation(s)
- Sarah H. Merkling
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Alfred W. Bronkhorst
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jamie M. Kramer
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Gijs J. Overheul
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Annette Schenck
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ronald P. Van Rij
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
- * E-mail:
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Kleefstra T, Schenck A, Kramer JM, van Bokhoven H. The genetics of cognitive epigenetics. Neuropharmacology 2014; 80:83-94. [PMID: 24434855 DOI: 10.1016/j.neuropharm.2013.12.025] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 12/29/2013] [Accepted: 12/30/2013] [Indexed: 01/31/2023]
Abstract
Cognitive disorders (CDs) are a heterogeneous group of disorders for which the genetic foundations are rapidly being uncovered. The large number of CD-associated gene mutations presents an opportunity to identify common mechanisms of disease as well as molecular processes that are of key importance to human cognition. Given the disproportionately high number of epigenetic genes associated with CD, epigenetic regulation of gene transcription is emerging as a process of major importance in cognition. The cognate protein products of these genes often co-operate in shared protein complexes or pathways, which is reflected in similarities between the neurodevelopmental phenotypes corresponding to these mutant genes. Here we provide an overview of the genes associated with CDs, and highlight some of the epigenetic regulatory complexes involving multiple CD genes. Such common gene networks may provide a handle for designing therapeutic interventions applicable to a number of cognitive disorders with variable genetic etiology.
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Affiliation(s)
- Tjitske Kleefstra
- Radboud University Medical Center, Department of Human Genetics, Nijmegen Center for Molecular Life Sciences (NCMLS), Nijmegen, The Netherlands
| | - Annette Schenck
- Radboud University Medical Center, Department of Human Genetics, Nijmegen Center for Molecular Life Sciences (NCMLS), Nijmegen, The Netherlands
| | - Jamie M Kramer
- Radboud University Medical Center, Department of Human Genetics, Nijmegen Center for Molecular Life Sciences (NCMLS), Nijmegen, The Netherlands
| | - Hans van Bokhoven
- Radboud University Medical Center, Department of Human Genetics, Nijmegen Center for Molecular Life Sciences (NCMLS), Nijmegen, The Netherlands; Radboud University Medical Center, Department of Cognitive Neurosciences, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.
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22
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Vandewalle J, Langen M, Zschaetzsch M, Nijhof B, Kramer JM, Brems H, Bauters M, Lauwers E, Srahna M, Marynen P, Verstreken P, Schenck A, Hassan BA, Froyen G. Ubiquitin ligase HUWE1 regulates axon branching through the Wnt/β-catenin pathway in a Drosophila model for intellectual disability. PLoS One 2013; 8:e81791. [PMID: 24303071 PMCID: PMC3841167 DOI: 10.1371/journal.pone.0081791] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 10/26/2013] [Indexed: 12/11/2022] Open
Abstract
We recently reported that duplication of the E3 ubiquitin ligase HUWE1 results in intellectual disability (ID) in male patients. However, the underlying molecular mechanism remains unknown. We used Drosophila melanogaster as a model to investigate the effect of increased HUWE1 levels on the developing nervous system. Similar to the observed levels in patients we overexpressed the HUWE1 mRNA about 2-fold in the fly. The development of the mushroom body and neuromuscular junctions were not altered, and basal neurotransmission was unaffected. These data are in agreement with normal learning and memory in the courtship conditioning paradigm. However, a disturbed branching phenotype at the axon terminals of the dorsal cluster neurons (DCN) was detected. Interestingly, overexpression of HUWE1 was found to decrease the protein levels of dishevelled (dsh) by 50%. As dsh as well as Fz2 mutant flies showed the same disturbed DCN branching phenotype, and the constitutive active homolog of β-catenin, armadillo, could partially rescue this phenotype, our data strongly suggest that increased dosage of HUWE1 compromises the Wnt/β-catenin pathway possibly by enhancing the degradation of dsh.
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Affiliation(s)
- Joke Vandewalle
- Human Genome Laboratory, VIB Center for the Biology of Disease, Leuven, Belgium
- Human Genome Laboratory, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Marion Langen
- Laboratory of Neurogenetics, VIB Center for the Biology of Disease, KU Leuven, Leuven, Belgium
| | - Marlen Zschaetzsch
- Laboratory of Neurogenetics, VIB Center for the Biology of Disease, KU Leuven, Leuven, Belgium
| | - Bonnie Nijhof
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour & Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jamie M. Kramer
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour & Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hilde Brems
- Laboratory for Neurofibromatosis Research, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Marijke Bauters
- Human Genome Laboratory, VIB Center for the Biology of Disease, Leuven, Belgium
- Human Genome Laboratory, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Elsa Lauwers
- Laboratory of Neuronal Communication, VIB Center for the Biology of Disease, KU Leuven, Leuven, Belgium
| | - Mohammed Srahna
- Laboratory of Neurogenetics, VIB Center for the Biology of Disease, KU Leuven, Leuven, Belgium
| | - Peter Marynen
- Human Genome Laboratory, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Patrik Verstreken
- Laboratory of Neuronal Communication, VIB Center for the Biology of Disease, KU Leuven, Leuven, Belgium
| | - Annette Schenck
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour & Radboud University Medical Center, Nijmegen, The Netherlands
| | - Bassem A. Hassan
- Laboratory of Neurogenetics, VIB Center for the Biology of Disease, KU Leuven, Leuven, Belgium
- * E-mail: (GF); (BAH)
| | - Guy Froyen
- Human Genome Laboratory, VIB Center for the Biology of Disease, Leuven, Belgium
- Human Genome Laboratory, Department of Human Genetics, KU Leuven, Leuven, Belgium
- * E-mail: (GF); (BAH)
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Gupta VK, Scheunemann L, Eisenberg T, Mertel S, Bhukel A, Koemans TS, Kramer JM, Liu KSY, Schroeder S, Stunnenberg HG, Sinner F, Magnes C, Pieber TR, Dipt S, Fiala A, Schenck A, Schwaerzel M, Madeo F, Sigrist SJ. Restoring polyamines protects from age-induced memory impairment in an autophagy-dependent manner. Nat Neurosci 2013; 16:1453-60. [PMID: 23995066 DOI: 10.1038/nn.3512] [Citation(s) in RCA: 236] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 08/08/2013] [Indexed: 11/08/2022]
Abstract
Age-dependent memory impairment is known to occur in several organisms, including Drosophila, mouse and human. However, the fundamental cellular mechanisms that underlie these impairments are still poorly understood, effectively hampering the development of pharmacological strategies to treat the condition. Polyamines are among the substances found to decrease with age in the human brain. We found that levels of polyamines (spermidine, putrescine) decreased in aging fruit flies, concomitant with declining memory abilities. Simple spermidine feeding not only restored juvenile polyamine levels, but also suppressed age-induced memory impairment. Ornithine decarboxylase-1, the rate-limiting enzyme for de novo polyamine synthesis, also protected olfactory memories in aged flies when expressed specifically in Kenyon cells, which are crucial for olfactory memory formation. Spermidine-fed flies showed enhanced autophagy (a form of cellular self-digestion), and genetic deficits in the autophagic machinery prevented spermidine-mediated rescue of memory impairments. Our findings indicate that autophagy is critical for suppression of memory impairments by spermidine and that polyamines, which are endogenously present, are candidates for pharmacological intervention.
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Affiliation(s)
- Varun K Gupta
- 1] Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany. [2] NeuroCure, Charité, Berlin, Germany
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Bhattacharyya I, Kramer JM. Clinical pathologic conference case 5: Unusual severe glossitis. Oral Surg Oral Med Oral Pathol Oral Radiol 2013; 115:e46-9. [PMID: 23738346 DOI: 10.1016/j.oooo.2013.01.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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van Bon BWM, Oortveld MAW, Nijtmans LG, Fenckova M, Nijhof B, Besseling J, Vos M, Kramer JM, de Leeuw N, Castells-Nobau A, Asztalos L, Viragh E, Ruiter M, Hofmann F, Eshuis L, Collavin L, Huynen MA, Asztalos Z, Verstreken P, Rodenburg RJ, Smeitink JA, de Vries BBA, Schenck A. CEP89 is required for mitochondrial metabolism and neuronal function in man and fly. Hum Mol Genet 2013; 22:3138-51. [PMID: 23575228 DOI: 10.1093/hmg/ddt170] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
It is estimated that the human mitochondrial proteome consists of 1000-1500 distinct proteins. The majority of these support the various biochemical pathways that are active in these organelles. Individuals with an oxidative phosphorylation disorder of unknown cause provide a unique opportunity to identify novel genes implicated in mitochondrial biology. We identified a homozygous deletion of CEP89 in a patient with isolated complex IV deficiency, intellectual disability and multisystemic problems. CEP89 is a ubiquitously expressed and highly conserved gene of unknown function. Immunocytochemistry and cellular fractionation experiments showed that CEP89 is present both in the cytosol and in the mitochondrial intermembrane space. Furthermore, we ascertained in vitro that downregulation of CEP89 resulted in a severe decrease in complex IV in-gel activity and altered mobility, suggesting that the complex is aberrantly formed. Two-dimensional BN-SDS gel analysis revealed that CEP89 associates with a high-molecular weight complex. Together, these data confirm a role for CEP89 in mitochondrial metabolism. In addition, we modeled CEP89 loss of function in Drosophila. Ubiquitous knockdown of fly Cep89 decreased complex IV activity and resulted in complete lethality. Furthermore, Cep89 is required for mitochondrial integrity, membrane depolarization and synaptic transmission of photoreceptor neurons, and for (sub)synaptic organization of the larval neuromuscular junction. Finally, we tested neuronal Cep89 knockdown flies in the light-off jump reflex habituation assay, which revealed its role in learning. We conclude that CEP89 proteins play an important role in mitochondrial metabolism, especially complex IV activity, and are required for neuronal and cognitive function across evolution.
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Affiliation(s)
- Bregje W M van Bon
- Department of Human Genetics, Radboud University Medical Centre, 6500 HB, Nijmegen, The Netherlands
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26
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Iqbal Z, Vandeweyer G, van der Voet M, Waryah AM, Zahoor MY, Besseling JA, Roca LT, Vulto-van Silfhout AT, Nijhof B, Kramer JM, Van der Aa N, Ansar M, Peeters H, Helsmoortel C, Gilissen C, Vissers LELM, Veltman JA, de Brouwer APM, Frank Kooy R, Riazuddin S, Schenck A, van Bokhoven H, Rooms L. Homozygous and heterozygous disruptions of ANK3: at the crossroads of neurodevelopmental and psychiatric disorders. Hum Mol Genet 2013; 22:1960-70. [PMID: 23390136 DOI: 10.1093/hmg/ddt043] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AnkyrinG, encoded by the ANK3 gene, is involved in neuronal development and signaling. It has previously been implicated in bipolar disorder and schizophrenia by association studies. Most recently, de novo missense mutations in this gene were identified in autistic patients. However, the causative nature of these mutations remained controversial. Here, we report inactivating mutations in the Ankyrin 3 (ANK3) gene in patients with severe cognitive deficits. In a patient with a borderline intelligence, severe attention deficit hyperactivity disorder (ADHD), autism and sleeping problems, all isoforms of the ANK3 gene, were disrupted by a balanced translocation. Furthermore, in a consanguineous family with moderate intellectual disability (ID), an ADHD-like phenotype and behavioral problems, we identified a homozygous truncating frameshift mutation in the longest isoform of the same gene, which represents the first reported familial mutation in the ANK3 gene. The causality of ANK3 mutations in the two families and the role of the gene in cognitive function were supported by memory defects in a Drosophila knockdown model. Thus we demonstrated that ANK3 plays a role in intellectual functioning. In addition, our findings support the suggested association of ANK3 with various neuropsychiatric disorders and illustrate the genetic and molecular relation between a wide range of neurodevelopmental disorders.
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Affiliation(s)
- Zafar Iqbal
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognitionand Behaviour, Radboud University Medical Centre, Nijmegen, TheNetherlands
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Kramer JM, Olsen S, Mermelstein M, Balcells A, Liljenquist K. Youth with disabilities' perspectives of the environment and participation: a qualitative meta-synthesis. Child Care Health Dev 2012; 38:763-77. [PMID: 22372695 DOI: 10.1111/j.1365-2214.2012.01365.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [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: 11/27/2022]
Abstract
Meta-syntheses can enhance our knowledge regarding the impact of the environment on the participation of youth with disabilities and generate theoretical frameworks to inform policy and best practices. The purpose of this study was to describe school-aged youth with disabilities' perspectives regarding the impact of the environment and modifications on their participation. A meta-synthesis systematically integrates qualitative evidence from multiple studies. Six databases were searched and 1287 citations reviewed for inclusion by two independent raters; 15 qualitative articles were selected for inclusion. Two independent reviewers evaluated the quality of each study and coded the results section. Patterns between codes within and across articles were examined using a constant comparative approach. Environments may be more or less inclusive for youth with disabilities depending upon others' understanding of individual abilities and needs, youth involvement in decisions about accommodations, and quality of services and policies. Youth implemented strategies to negotiate environmental barriers and appraised the quality of their participation based on the extent to which they engaged alongside peers. This meta-synthesis generated a framework illustrating the relationship between the environment, modifications and participation, and provided a conceptualization of participation grounded in the lived experiences of youth with disabilities. Findings reveal gaps in current knowledge and highlight the importance of involving youth with disabilities in decision making.
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Affiliation(s)
- J M Kramer
- Department of Occupational Therapy, Boston University, Boston, MA 02215, USA.
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Kramer JM, Kochinke K, Oortveld MAW, Marks H, Kramer D, de Jong EK, Asztalos Z, Westwood JT, Stunnenberg HG, Sokolowski MB, Keleman K, Zhou H, van Bokhoven H, Schenck A. Epigenetic regulation of learning and memory by Drosophila EHMT/G9a. PLoS Biol 2011; 9:e1000569. [PMID: 21245904 PMCID: PMC3014924 DOI: 10.1371/journal.pbio.1000569] [Citation(s) in RCA: 149] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Accepted: 11/10/2010] [Indexed: 11/18/2022] Open
Abstract
The epigenetic modification of chromatin structure and its effect on complex neuronal processes like learning and memory is an emerging field in neuroscience. However, little is known about the "writers" of the neuronal epigenome and how they lay down the basis for proper cognition. Here, we have dissected the neuronal function of the Drosophila euchromatin histone methyltransferase (EHMT), a member of a conserved protein family that methylates histone 3 at lysine 9 (H3K9). EHMT is widely expressed in the nervous system and other tissues, yet EHMT mutant flies are viable. Neurodevelopmental and behavioral analyses identified EHMT as a regulator of peripheral dendrite development, larval locomotor behavior, non-associative learning, and courtship memory. The requirement for EHMT in memory was mapped to 7B-Gal4 positive cells, which are, in adult brains, predominantly mushroom body neurons. Moreover, memory was restored by EHMT re-expression during adulthood, indicating that cognitive defects are reversible in EHMT mutants. To uncover the underlying molecular mechanisms, we generated genome-wide H3K9 dimethylation profiles by ChIP-seq. Loss of H3K9 dimethylation in EHMT mutants occurs at 5% of the euchromatic genome and is enriched at the 5' and 3' ends of distinct classes of genes that control neuronal and behavioral processes that are corrupted in EHMT mutants. Our study identifies Drosophila EHMT as a key regulator of cognition that orchestrates an epigenetic program featuring classic learning and memory genes. Our findings are relevant to the pathophysiological mechanisms underlying Kleefstra Syndrome, a severe form of intellectual disability caused by mutations in human EHMT1, and have potential therapeutic implications. Our work thus provides novel insights into the epigenetic control of cognition in health and disease.
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Affiliation(s)
- Jamie M. Kramer
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Korinna Kochinke
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Merel A. W. Oortveld
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Hendrik Marks
- Radboud University Nijmegen, Department of Molecular Biology, Nijmegen Centre for Molecular Life Sciences, Faculty of Science, Nijmegen, The Netherlands
| | - Daniela Kramer
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Eiko K. de Jong
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Zoltan Asztalos
- Aktogen Ltd., Department of Genetics, University of Cambridge, Cambridge, United Kingdom
- Institute of Biochemistry, Biological Research Center of Hungarian Academy of Sciences, Szeged, Hungary
| | | | - Hendrik G. Stunnenberg
- Radboud University Nijmegen, Department of Molecular Biology, Nijmegen Centre for Molecular Life Sciences, Faculty of Science, Nijmegen, The Netherlands
| | | | | | - Huiqing Zhou
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Hans van Bokhoven
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- Department of Cognitive Neurosciences, Donders Institute for Brain, Cognition and Behavior; Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- * E-mail: (AS); (HvB)
| | - Annette Schenck
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- * E-mail: (AS); (HvB)
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van Bokhoven H, Kramer JM. Disruption of the epigenetic code: an emerging mechanism in mental retardation. Neurobiol Dis 2010; 39:3-12. [PMID: 20304068 DOI: 10.1016/j.nbd.2010.03.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Revised: 03/10/2010] [Accepted: 03/12/2010] [Indexed: 01/18/2023] Open
Abstract
Mental retardation (MR) is a highly diverse group of cognitive disorders. Gene defects account for about half of all patients and mutations causative for impaired cognition have been identified in more than 400 genes. While there are numerous genetic defects underlying MR, a more limited number of pathways is emerging whose disruption appears to be shared by groups of MR genes. One of these common pathways is composed of MR genes that encode regulators of chromatin structure and of chromatin-mediated transcription regulation. Already more than 20 "epigenetic MR genes" have been identified and this number is likely to increase in the coming years when deep sequencing of exomes and genomes will become commonplace. Prominent examples of epigenetic MR genes include the methyl CpG-binding protein MECP2 and the CREB binding protein, CBP. Interestingly, several epigenetic MR proteins have been found to interact directly with one another or act together in complexes that regulate the local chromatin structure at target genes. Thus, it appears that the functions of individual epigenetic MR proteins converge onto similar biological processes that are crucial to neuronal processes. The next challenge will be to gain more insight into patterns of altered DNA methylation and histone modifications that are caused by epigenetic gene mutations and how these will disrupt the brain-specific expression of target genes. Such research may reveal that a wide variety of mutations in the genetic code result in a more limited number of disruptions to the epigenetic code. If so, this will provide a rationale for therapeutic strategies.
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Affiliation(s)
- Hans van Bokhoven
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
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Cliffe ST, Kramer JM, Hussain K, Robben JH, de Jong EK, de Brouwer AP, Nibbeling E, Kamsteeg EJ, Wong M, Prendiville J, James C, Padidela R, Becknell C, van Bokhoven H, Deen PMT, Hennekam RCM, Lindeman R, Schenck A, Roscioli T, Buckley MF. SLC29A3 gene is mutated in pigmented hypertrichosis with insulin-dependent diabetes mellitus syndrome and interacts with the insulin signaling pathway. Hum Mol Genet 2009; 18:2257-65. [PMID: 19336477 DOI: 10.1093/hmg/ddp161] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Pigmented hypertrichotic dermatosis with insulin-dependent diabetes (PHID) syndrome is a recently described autosomal recessive disorder associated with predominantly antibody negative, insulin-dependent diabetes mellitus. In order to identify the genetic basis of PHID and study its relationship with glucose metabolism, we performed homozygosity mapping in five unrelated families followed by candidate gene sequencing. Five loss-of-function mutations were identified in the SLC29A3 gene which encodes a member of a highly conserved protein family that transports nucleosides, nucleobases and nucleoside analogue drugs, hENT3. We show that PHID is allelic with a related syndrome without diabetes mellitus, H syndrome. The interaction of SLC29A3 with insulin signaling pathways was then studied using an established model in Drosophila melanogaster. Ubiquitous knockdown of the Drosophila ortholog of hENT3, dENT1 is lethal under stringent conditions; whereas milder knockdown induced scutellar bristle phenotypes similar to those previously reported in the knockdown of the Drosophila ortholog of the Islet gene. A cellular growth assay showed a reduction of cell size/number which could be rescued or enhanced by manipulation of the Drosophila insulin receptor and its downstream signaling effectors, dPI3K and dAkt. In summary, inactivating mutations in SLC29A3 cause a syndromic form of insulin-dependent diabetes in humans and in Drosophila profoundly affect cell size/number through interactions with the insulin signaling pathway. These data suggest that further investigation of the role of SLC29A3 in glucose metabolism is a priority for diabetes research.
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Affiliation(s)
- Simon T Cliffe
- Department of Haematology and Genetics, South Eastern Area Laboratory Services, Sydney, NSW 2031, Australia
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Kramer JM, Evans A, Drury K, Moore K. Calyculin-A improves chromosome condensation for cytogenetic analysis of blastomeres from bovine and murine eight-cell stage embryos. Theriogenology 2008; 70:692-703. [PMID: 18556054 DOI: 10.1016/j.theriogenology.2008.04.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2007] [Revised: 04/21/2008] [Accepted: 04/23/2008] [Indexed: 11/25/2022]
Abstract
This study evaluated the serine/threonine phosphatase inhibitor calyculin-A for rapid, efficient induction of premature chromosome condensation (PCC) in blastomeres obtained from Day 3 bovine and Day 2 murine eight-cell stage embryos, and its potential for use in cytogenetic analysis. Experiment 1 tested calyculin-A duration (0, 60, 120, and 180min) to induce PCC in bovine blastomeres. More blastomeres that underwent PCC had chromosomes suitable for cytogenetic analysis if treated for 120 or 180min (P<0.005). Experiment 2 compared doses of calyculin-A (0, 10, 50, and 100nM) on bovine blastomeres; calyculin-A (50nM, 120min) induced PCC suitable for cytogenetic analysis in the greatest number of blastomeres when compared to other doses (52.5%; P<0.005). Effects of calyculin-A (50nM) on murine blastomeres at durations of 0, 60, 90, and 120min to induce PCC were tested in Experiment 3, with 90min inducing the highest frequency of condensed chromosomes suitable for cytogenetic analysis (34%; P<0.05). Finally, Experiment 4 evaluated calyculin-A treated bovine embryos under optimal conditions (50nM, 120min) for use in gender and cytogenetic analysis. Whole chromosome paint probes were successfully hybridized to chromosomes along with 4',6-diamidino-2-phenylindole dihydrochloride hydrate (DAPI) counterstaining, allowing detection of embryo gender (54% F:46% M) and ploidy of individual blastomeres within embryos (64% diploid:36% mixoploid embryos). In conclusion, we inferred that calyculin-A was useful for rapid induction of PCC, producing chromosome spreads suitable for cytogenetic analysis of blastomeres in G1 or G2/M phase of the cell cycle.
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Affiliation(s)
- J M Kramer
- Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
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Abstract
The ability of an organism to alter its metabolism, growth, and reproductive capacity in response to fluctuations in food availability has likely been an important factor in the course of evolution. The insulin signalling pathway is an evolutionarily conserved mechanism used by metazoan animals to sense and respond to changes in nutrient intake. During conditions of starvation the level of circulating insulin is low. Under conditions of low insulin, the foxo family of transcription factors are activated. Studies in Drosophila suggest that Drosophila foxo may alter the transcriptional profile of cells to allow for maximum survival of the fly during starvation. We have tested this ability in transgenic flies containing a luciferase reporter gene under the control of foxo response elements. We show that foxo activity is increased during amino acid starvation and reduced in the presence of amino acids. In addition, we find that loss of function of foxo leads to reduced survival under conditions of amino acid starvation in both larvae and adult flies. These data provide direct evidence that foxo is activated during amino acid starvation and is critical for optimal survival under these conditions.
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Affiliation(s)
- Jamie M. Kramer
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL A1B 3X9, Canada
| | - Jennifer D. Slade
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL A1B 3X9, Canada
| | - Brian E. Staveley
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL A1B 3X9, Canada
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Curtis JR, Kramer JM, Martin C, Saag KG, Patkar N, Shatin D, Burgess M, Xie A, Braun MM. Heart failure among younger rheumatoid arthritis and Crohn's patients exposed to TNF-alpha antagonists. Rheumatology (Oxford) 2007; 46:1688-93. [PMID: 17938138 DOI: 10.1093/rheumatology/kem212] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVES New onset heart failure (HF) has been associated with the use of TNF-alpha antagonists etanercept and infliximab based upon spontaneous adverse event reports. HF clinical trials of these agents were stopped early due to futility or worsening of existing HF. A potential association between etanercept and infliximab and new onset HF has been studied minimally at a population level. METHODS Using administrative claims from a large U.S. health care organization, we identified rheumatoid arthritis (RA) and Crohn's disease (CD) patients receiving infliximab or etanercept (exposed), and comparator cohorts of RA and CD patients receiving non-biologic immunosuppressives (unexposed). We studied adults < 50 years to reduce potential confounding related to common age-related comorbidities. Based on abstracted medical records of suspected HF cases, a physician panel adjudicated cases as definite, possible or no HF. RESULTS Among 4018 RA and CD patients with mean duration follow-up of 18 months, 9 of 33 suspected HF cases (identified using claims data) were adjudicated as definite (n = 5) or possible (n = 4) HF. The relative risk of HF among TNF-alpha antagonist-treated RA and CD patients was 4.3 and 1.2, respectively (P = NS for both). The absolute difference in cumulative incidence of HF among infliximab or etanercept-exposed compared to unexposed patients was 3.4 and 0.3 cases per 1000 persons for RA and CD (P = NS), respectively, yielding a number needed to harm of 294 for RA and 3333 for CD. CONCLUSION We found only a small number of presumed HF cases (n = 9, or 0.2%) in a large population of relatively young RA and CD patients. Although there was an increased relative risk of incident, HF that was not statistically significant among those exposed to TNF-alpha antagonists compared to those unexposed, larger cohorts are needed to provide more precise risk estimates and permit adjustment for potential confounding.
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Affiliation(s)
- J R Curtis
- Center for Education and Research on Therapeutics of Musculoskeletal Disorders, The University of Alabama at Birmingham, Birmingham, AL, USA
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Moore K, Kramer JM, Rodriguez-Sallaberry CJ, Yelich JV, Drost M. Insulin-like growth factor (IGF) family genes are aberrantly expressed in bovine conceptuses produced in vitro or by nuclear transfer. Theriogenology 2007; 68:717-27. [PMID: 17628655 DOI: 10.1016/j.theriogenology.2007.06.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2006] [Accepted: 06/06/2007] [Indexed: 11/19/2022]
Abstract
Embryos produced through somatic cell nuclear transfer (NT) or in vitro production (IVP) are often associated with increased abortion and abnormalities thought to arise from disruptions in normal gene expression. The insulin-like growth factor (IGF) family has a major influence on embryonic, fetal and placental development; differences in IGF expression in NT- and IVP-derived embryos may account for embryonic losses during placental attachment. In the present study, expression of IGF-I, IGF-II, IGF-I receptor (IGF-IR), and IGF-IIR mRNAs was quantitated in Day 7 and 25 bovine embryos produced in vivo, by NT, IVP, or parthenogenesis, to further understand divergent changes occurring during development. Expression of the IGF-I gene was not detected in Day 7 blastocysts for any treatment. However, there were no differences (P>0.10) among Day 7 treatments in the amounts of IGF-IR, IGF-II, and IGF-IIR mRNA. For Day 25 conceptuses, there was higher expression of IGF-I mRNA for NT and IVP embryonic tissues than for in vivo embryonic tissues (P<0.05). Furthermore, embryonic tissues from NT-derived embryos had higher expression of IGF-II mRNA than IVP embryonic tissues (P<0.05). Placental expression of IGF-IIR mRNA was greater for NT-derived than in vivo-derived embryos (P<0.05). There were no differences in IGF-IR mRNA across all treatments and tissues (P>0.10). In conclusion, these differences in growth factor gene expression during early placental attachment and rapid embryonic growth may directly or indirectly contribute to increased losses and abnormalities in IVP- and NT-derived embryos.
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Affiliation(s)
- K Moore
- Department of Animal Sciences, Institute of Food and Agriculture Sciences, University of Florida, Gainesville, FL 32611-0910, USA.
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35
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Kramer JM, Davidge JT, Lockyer JM, Staveley BE. Expression of Drosophila FOXO regulates growth and can phenocopy starvation. BMC Dev Biol 2003; 3:5. [PMID: 12844367 PMCID: PMC183841 DOI: 10.1186/1471-213x-3-5] [Citation(s) in RCA: 157] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2003] [Accepted: 07/05/2003] [Indexed: 01/04/2023]
Abstract
BACKGROUND Components of the insulin signaling pathway are important regulators of growth. The FOXO (forkhead box, sub-group "O") transcription factors regulate cellular processes under conditions of low levels of insulin signaling. Studies in mammalian cell culture show that activation of FOXO transcription factors causes cell death or cell cycle arrest. The Caenorhabditis elegans homologue of FOXO, Daf-16, is required for the formation of dauer larvae in response to nutritional stress. In addition, FOXO factors have been implicated in stress resistance and longevity. RESULTS We have identified the Drosophila melanogaster homologue of FOXO (dFOXO), which is conserved in amino acid sequence compared with the mammalian FOXO homologues and Daf-16. Expression of dFOXO during early larval development causes inhibition of larval growth and alterations in feeding behavior. Inhibition of larval growth is reversible upon discontinuation of dFOXO expression. Expression of dFOXO during the third larval instar or at low levels during development leads to the generation of adults that are reduced in size. Analysis of the wings and eyes of these small flies indicates that the reduction in size is due to decreases in cell size and cell number. Overexpression of dFOXO in the developing eye leads to a characteristic phenotype with reductions in cell size and cell number. This phenotype can be rescued by co-expression of upstream insulin signaling components, dPI3K and dAkt, however, this rescue is not seen when FOXO is mutated to a constitutively active form. CONCLUSIONS dFOXO is conserved in both sequence and regulatory mechanisms when compared with other FOXO homologues. The establishment of Drosophila as a model for the study of FOXO transcription factors should prove beneficial to determining the biological role of these signaling molecules. The alterations in larval development seen upon overexpression of dFOXO closely mimic the phenotypic effects of starvation, suggesting a role for dFOXO in the response to nutritional adversity. This work has implications in the understanding of cancer and insulin related disorders, such as diabetes and obesity.
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Affiliation(s)
- Jamie M Kramer
- Department of Biology,
Memorial University of Newfoundland, St. John's, Newfoundland, (A1B
3X9), Canada
| | - Jason T Davidge
- Department of Biology,
Memorial University of Newfoundland, St. John's, Newfoundland, (A1B
3X9), Canada
| | - Joseph M Lockyer
- Department of Biology,
Memorial University of Newfoundland, St. John's, Newfoundland, (A1B
3X9), Canada
| | - Brian E Staveley
- Department of Biology,
Memorial University of Newfoundland, St. John's, Newfoundland, (A1B
3X9), Canada
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36
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Kramer JM, Staveley BE. GAL4 causes developmental defects and apoptosis when expressed in the developing eye of Drosophila melanogaster. Genet Mol Res 2003; 2:43-7. [PMID: 12917801] [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: 03/04/2023]
Abstract
The UAS/GAL4 ectopic expression system is widely used in Drosophila melanogaster for the overexpression of transgenes. This system operates under the assumption that the yeast transcription factor, GAL4, is inactive in D. melanogaster. Thus, GAL4 can be expressed under the control of D. melanogaster -specific promoters with little effect upon the organism. We have shown that expression of GAL4 in the developing eye under the control of the glass multiple reporter (GMR) promoter element does have an effect on eye development. Although GMR-GAL4 heterozygotes appear normal when raised at 25 degrees C, the homozygotes have a highly disorganized ommatidial array. In addition, the levels of apoptosis in the third-instar larval eye imaginal disc (where GAL4 is expressed) are slightly higher in GMR-GAL4 heterozygotes, and much higher in GMR-GAL4 homozygotes when compared to wild type discs. The morphological eye defects caused by GMR-GAL4 are significantly enhanced when flies are raised at 29 degrees C (presumably due to the higher activity of GAL4 at this temperature); however, the levels of apoptosis appear to be similar at these two temperatures. Taken together, these data suggest that GAL4 can have adverse effects on D. melanogaster development, especially at high expression levels. In addition, GAL4 appears to induce apoptosis even in the absence of any visible morphological defects. Thus, despite the benefits of the UAS/GAL4 ectopic expression system, one must use caution in the design and interpretation of experiments.
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Affiliation(s)
- Jamie M Kramer
- Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1B 3X9
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Little HR, Kramer JM, Beatty JA, Waldrop TG. Chronic exercise increases GAD gene expression in the caudal hypothalamus of spontaneously hypertensive rats. Brain Res Mol Brain Res 2001; 95:48-54. [PMID: 11687276 DOI: 10.1016/s0169-328x(01)00239-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Previous studies have suggested that a gamma-amino-butyric acid (GABA) deficit in the caudal hypothalamus (CH) of the spontaneously hypertensive rat (SHR) contributes to elevated levels of arterial pressure. The purpose of this study was to examine if SHR that underwent exercise training demonstrated a blunted development of hypertension and greater levels of glutamic acid decarboxylase (GAD) mRNA transcripts in the caudal hypothalamus. SHR were randomly paired and assigned to either a trained group (T; n=9) or a non-trained control group (NT; n=9). Trained animals were exercised for 10 weeks on a motorized treadmill while NT animals concurrently rested on a mock-treadmill. Following the 10-week training period, Northern blot analyses of mRNA for both the 65-kDa (GAD(65)) and 67-kDa (GAD(67)) isoforms of GAD were performed on tissue from caudal hypothalamic and cerebellar control brain regions. Exercise training simultaneously blunted the developmental rise in blood pressure in SHR (Delta59+/-9 mmHg in trained versus Delta77+/-9 mmHg in non-trained; P<0.03) and increased both GAD(65) (147+/-44%) and GAD(67) (162+/-77%) mRNA transcript levels in the CH (P<0.05). In contrast, no difference was detected in GAD mRNA levels in the cerebellum between T and NT SHR. These findings are consistent with our previous functional studies and demonstrate that exercise can significantly and specifically upregulate GAD gene transcript levels in the caudal hypothalamus of hypertensive rats.
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Affiliation(s)
- H R Little
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, 61801, USA
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38
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Kramer JM, Waldrop TG, Frizzell LA, Zachary JF, O'Brien WD. Cardiopulmonary function in rats with lung hemorrhage induced by pulsed ultrasound exposure. J Ultrasound Med 2001; 20:1197-1206. [PMID: 11758025 DOI: 10.7863/jum.2001.20.11.1197] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
OBJECTIVE To assess cardiopulmonary function in rats exposed to pulsed ultrasound using superthreshold exposure conditions known to produce significant lung hemorrhage. METHODS In 1 group of 9 anesthetized Sprague-Dawley rats, 5 foci of ultrasound-induced hemorrhage were produced in the left lung of each rat. In a second group of 6 rats, 5 foci of ultrasound-induced hemorrhage were produced in the left and right lungs of each rat. Each lesion was induced using superthreshold pulsed ultrasound exposure conditions (3.1-MHz center frequency, 1.7-kHz pulse repetition frequency, 1.3-micro-second pulse duration, 60-second exposure duration, 39-MPa in situ peak compressional pressure, and 17-MPa in situ peak rarefactional pressure). After exposure, the lungs were fixed in formalin and assessed histologically. The total lesion volume was calculated for each lesion in each lung lobe. Measurements of cardiopulmonary function included assessment of pulsatile arterial pressure, heart rate, end-tidal carbon dioxide, respiratory rate, and arterial blood gases (PCO2 and PO2). Functional data were quantified before (baseline) and 30 minutes after exposure to ultrasound. RESULTS In the 9 rats that had lesions in only the left lung, the mean (SEM) lesion volume was 97 (13) mm3 and represented about 3.4% of the total lung volume. In the 6 rats that had lesions in both the left and right lungs, the left, right, and total mean lesion volumes, respectively, were 102 (16), 114 (11), and 216 (18) mm3 and represented about 3.7%, 4.2%, and 7.9% of the total lung volume. There were no statistically significant differences in cardiopulmonary measurements between baseline values and values obtained after exposure to ultrasound in the 9 rats exposed on the left lung only. The 6 rats exposed bilaterally had statistically significant differences in arterial pressure (134 +/- 4 versus 113 +/- 9 mm Hg; P= .047) and arterial PO2 (70 +/- 5 versus 58 +/- 4 mm Hg; P = .024) between baseline values and values obtained after exposure to ultrasound. CONCLUSIONS The severity of ultrasound-induced lesions produced in 1 lung did not affect measurements of cardiopulmonary function because of the functional respiratory reserve in the unexposed lung. However, when both the left and right lungs had ultrasound-induced lesions, the functional respiratory reserve was decreased to a point at which rats were unable to maintain systemic arterial pressure or resting levels of arterial PO2.
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Affiliation(s)
- J M Kramer
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, 61801, USA
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Abstract
We examined the cardiovascular and ventrolateral medullary neuronal responses to muscle contraction in the spontaneously hypertensive rat (SHR) and normotensive Wistar-Kyoto rat (WKY) control. Cardiovascular, respiratory and ventrolateral medullary neuronal responses to muscle contraction evoked by tibial nerve stimulation were recorded. SHRs exhibited significantly larger drops in arterial pressure compared to WKYs in response to muscle contraction (P < 0.05). Basal ventrolateral medulla neuronal discharge rates were similar between the SHR and the WKY groups. A majority of neurons recorded responded to muscle contraction in both the WKY (77 %; n = 53) and the SHR groups (68 %; n = 62). There was no difference in the percentage of neurons that responded with an increase (approximately 60 %) or decrease (approximately 40 %) in firing rate between hypertensive and normotensive rats. Pulse wave-triggered averaging techniques showed that most neurons that responded to muscle contraction also possessed a basal firing rhythm temporally related to the cardiac cycle (85 % in WKYs, 83 % in SHRs). However, decreases in neuronal firing rates in response to muscle contraction were significantly greater in SHRs than WKYs. Therefore, we conclude that muscle contraction unmasks a hyperexcitability of neurons in the ventrolateral medulla of SHRs that parallels the heightened blood pressure responses.
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Affiliation(s)
- J M Kramer
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, 61801, USA.
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Kramer JM, LaRussa P, Tsai WC, Carney P, Leber SM, Gahagan S, Steinberg S, Blackwood RA. Disseminated vaccine strain varicella as the acquired immunodeficiency syndrome-defining illness in a previously undiagnosed child. Pediatrics 2001; 108:E39. [PMID: 11483849 DOI: 10.1542/peds.108.2.e39] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [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] [Indexed: 11/24/2022] Open
Abstract
The Food and Drug Administration licensed a live-virus varicella vaccine (Varivax; Merck & Co Inc, West Point, PA) in March 1995. Prelicensure adverse events were minimal; however, since licensure and increased vaccine use, rare previously undetected risks have arisen. Presented here is the clinical course of a previously undiagnosed, human immunodeficiency virus-infected boy who developed dissemination of the vaccine strain of varicella zoster after immunization. chickenpox, human immunodeficiency virus, pneumonia, encephalopathy, varicella vaccine, adverse events, dissemination.
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Affiliation(s)
- J M Kramer
- Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, USA
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Abstract
AIMS To determine the frequency of coinfection with multiple strains in sporadic cases of human Campylobacter infection. METHOD AND RESULTS During 1999 10 single colonies of Campylobacter were cultured from each of 53 positive faecal samples. Five isolates were taken from nonselective agar after passive filtration of faecal suspensions and five isolates were taken from selective agar plates. All isolates were sero- and phage typed and their antibiotic resistance determined. Pulsed-field gel electrophoresis and flagellin gene typing were performed on selected isolates. One patient was infected with Camp. coli, the remainder with strains of Camp. jejuni. The majority of patients was infected with a single strain of Campylobacter, but from each of four samples, 7.5%, two strains of Camp. jejuni, confirmed by molecular typing, were identified. CONCLUSION Coinfection occurs in sporadic cases of campylobacteriosis. SIGNIFICANCE AND IMPACT OF THE STUDY This study has implications in outbreak investigation when distinct strains have been isolated from epidemiologically related patients and/or the suspected source or vehicle.
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Affiliation(s)
- J F Richardson
- Campylobacter Reference Unit, Laboratory of Enteric Pathogens, Central Public Health Laboratory, London, UK.
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42
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Abstract
The caudal hypothalamus is an important CNS site controlling cardiorespiratory integration during systemic hypoxia. Previous findings from this laboratory have identified caudal hypothalamic neurons of anesthetized rats that are stimulated during hypoxia. In addition, patch-clamp recordings in an in vitro brain slice preparation have revealed that there is an age-dependent response to hypoxia in caudal hypothalamic neurons. The present study utilized the expression of the transcription factor Fos as an indicator of neuronal depolarization to determine the hypoxic response of caudal hypothalamic neurons throughout postnatal development in conscious rats. Sprague-Dawley rats, aged three to 56 days, were placed in a normobaric chamber circulated with either 10% oxygen or room air for 3h. Following the hypoxic/normoxic exposure period, tissues from the caudal hypothalamus, periaqueductal gray, rostral ventrolateral medulla and nucleus tractus solitarius were processed immunocytochemically for the presence of the Fos protein. There was a significant increase in the density of neurons expressing Fos in the caudal hypothalamus of hypoxic compared to normoxic adult rats that was maintained in the absence of peripheral chemoreceptors. In contrast, no increase in the density of Fos-expressing caudal hypothalamic neurons was observed during hypoxia in rats less than 12 days old. Increases in Fos expression were also observed in an age-dependent manner in the periaqueductal gray, rostral ventrolateral medulla and nucleus tractus solitarius. These results show an increase in Fos expression in caudal hypothalamic neurons during hypoxia in conscious rats throughout development, supporting the earlier in vitro reports suggesting that these neurons are stimulated by hypoxia.
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Affiliation(s)
- E M Horn
- Department of Molecular and Integrative Physiology, Neuroscience Program, and College of Medicine, University of Illinois, Urbana, IL 61803, USA
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Kramer JM, Beatty JA, Little HR, Plowey ED, Waldrop TG. Chronic exercise alters caudal hypothalamic regulation of the cardiovascular system in hypertensive rats. Am J Physiol Regul Integr Comp Physiol 2001; 280:R389-97. [PMID: 11208566 DOI: 10.1152/ajpregu.2001.280.2.r389] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies have documented a deficit in the GABA neurotransmitter system within the caudal hypothalamus (CH) of spontaneously hypertensive rats (SHR). The reduction in inhibitory influence on this cardiovascular excitatory brain region is associated with an increased neuronal activity and resting blood pressure. The purpose of this study was to determine if chronic treadmill and wheel-running activities alter the ability of the CH to regulate cardiovascular function. SHR were exercised on a treadmill (5 times/wk) at moderate intensity or allowed free access to running wheels (7 days/wk) for a period of 10 wk. Resting blood pressures were obtained before and after the exercise training periods. After the exercise period, rats were anesthetized and microinjection experiments were performed. Treadmill-trained SHR exhibited a significantly blunted developmental rise in resting blood pressure after 10 wk of exercise. A similar yet less marked effect was observed in wheel-run rats. Microinjection of the GABA synthesis inhibitor 3-mercaptopropionic acid (3-MP) into the CH of nonexercised SHR did not produce any change in arterial pressure. In contrast, microinjection of 3-MP into the CH produced significant increases in blood pressure and heart rate in exercised SHR. These results demonstrate that exercise training can alter CH cardiovascular regulation in hypertensive rats and therefore may play a role in increasing cardiovascular health.
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Affiliation(s)
- J M Kramer
- Department of Molecular and Integrative Physiology and College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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Abstract
The cardiovascular responses induced by exercise are initiated by two primary mechanisms: central command and reflexes originating in exercising muscles. Although our understanding of cardiovascular responses to exercise in mice is progressing, a murine model of cardiovascular responses to muscle contraction has not been developed. Therefore, the purpose of this study was to characterize the cardiovascular responses to muscular contraction in anesthetized mice. The results of this study indicate that mice demonstrate significant increases in blood pressure (13.8 +/- 1.9 mmHg) and heart rate (33.5 +/- 11.9 beats/min) to muscle contraction in a contraction-intensity-dependent manner. Mice also demonstrate 23.1 +/- 3.5, 20.9 +/- 4.0, 21.7 +/- 2.6, and 25.8 +/- 3.0 mmHg increases in blood pressure to direct stimulation of tibial, peroneal, sural, and sciatic hindlimb somatic nerves, respectively. Systemic hypoxia (10% O(2)-90% N(2)) elicits increases in blood pressure (11.7 +/- 2.6 mmHg) and heart rate (42.7 +/- 13.9 beats/min), while increasing arterial pressure with phenylephrine decreases heart rate in a dose-dependent manner. The results from this study demonstrate the feasibility of using mice to study neural regulation of cardiovascular function during a variety of autonomic stimuli, including exercise-related drives such as muscle contraction.
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Affiliation(s)
- J M Kramer
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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45
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Blum JB, Kramer JM, Johnson KB. The palm as a real-time wide-area data-access device. Proc AMIA Symp 2001:52-6. [PMID: 11833481 PMCID: PMC2243283] [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: 02/23/2023] Open
Abstract
Handheld wireless technologies offer great promise in helping to improve healthcare. However, it is not clear whether off-the-shelf wireless networking will work as well within medical centers as this technology works outside of the medical center. Therefore, we evaluated the coverage of wide-area wireless technology within two representative academic medical centers. The study determined the rate of connectivity by testing both the Palm VII and the Minstrel V modem in a set of locations typically frequented by house staff in their daily activities. Within one hospital, connectivity was 59% for OmniSky service, and 78% for Palm.net. The second hospital's connectivity was over 93% with both devices. Differences in connectivity were likely due to the number of rooms visited with externally exposed walls, the suburban versus urban location of the academic medical center, and the relative location of service transponders. When examined by the Johns Hopkins Clinical Devices Laboratory, both devices were found to operate without interfering with other hospital equipment.
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Affiliation(s)
- J B Blum
- The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Kramerova IA, Kawaguchi N, Fessler LI, Nelson RE, Chen Y, Kramerov AA, Kusche-Gullberg M, Kramer JM, Ackley BD, Sieron AL, Prockop DJ, Fessler JH. Papilin in development; a pericellular protein with a homology to the ADAMTS metalloproteinases. Development 2000; 127:5475-85. [PMID: 11076767 DOI: 10.1242/dev.127.24.5475] [Citation(s) in RCA: 93] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Papilin is an extracellular matrix glycoprotein that we have found to be involved in, (1) thin matrix layers during gastrulation, (2) matrix associated with wandering, phagocytic hemocytes, (3) basement membranes and (4) space-filling matrix during Drosophila development. Determination of its cDNA sequence led to the identification of Caenorhabditis and mammalian papilins. A distinctly conserved ‘papilin cassette’ of domains at the amino-end of papilins is also the carboxyl-end of the ADAMTS subgroup of secreted, matrix-associated metalloproteinases; this cassette contains one thrombospondin type 1 (TSR) domain, a specific cysteine-rich domain and several partial TSR domains. In vitro, papilin non-competitively inhibits procollagen N-proteinase, an ADAMTS metalloproteinase. Inhibiting papilin synthesis in Drosophila or Caenorhabditis causes defective cell arrangements and embryonic death. Ectopic expression of papilin in Drosophila causes lethal abnormalities in muscle, Malpighian tubule and trachea formation. We suggest that papilin influences cell rearrangements and may modulate metalloproteinases during organogenesis.
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Affiliation(s)
- I A Kramerova
- MCD Biology Department and Molecular Biology Institute, University of California at Los Angeles, CA 90095, USA
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Kramer JM, Frost JA, Bolton FJ, Wareing DR. Campylobacter contamination of raw meat and poultry at retail sale: identification of multiple types and comparison with isolates from human infection. J Food Prot 2000; 63:1654-9. [PMID: 11131886 DOI: 10.4315/0362-028x-63.12.1654] [Citation(s) in RCA: 208] [Impact Index Per Article: 8.7] [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: 11/11/2022]
Abstract
Campylobacter species are the major cause of acute bacterial enteritis reported in the United Kingdom, nonetheless many aspects of campylobacteriosis epidemiology remain poorly understood. The aim of this study was to determine the prevalence of Campylobacter jejuni and Campylobacter coli in fresh bovine, ovine, and porcine liver and chicken portions from retail outlets and compare strain subtype distributions with those associated with cases of human campylobacteriosis occurring within the same period and study area. Meat samples were examined by both enrichment culture and direct plating, and Campylobacter isolates were subjected to the same test procedures (identification, serotyping, phagetyping, resistotyping) applied to the clinical strains. Campylobacter species were isolated from 73.2% of 489 samples examined. Chicken exhibited the highest contamination rate (83.3%), followed by lamb (72.9%), pig (71.7%), and ox (54.2%) liver. C. jejuni predominated in chicken (77.3%), lamb (75.0%), and ox (49.0%) liver, and C. coli predominated in pigs' liver (42.4%). Campylobacter fetus was identified in 12.5% of ox liver samples and also in pig and lamb. Of the human isolates, 89.3% were C. jejuni and 10.7% C. coli. The greatest variation in C. jeuni subtypes was observed among the chicken isolates (57 sero/phage-types), followed by human (48 types) and lamb (30 types). A significant proportion of the chicken and lamb isolates shared identical subtypes with the human strains, indicative of their role as potential sources of infection. Almost 30% of samples yielded multiple strains of Campylobacter, a finding that reinforces the epidemiological importance of selecting and testing more than one presumptive isolate per sample.
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Affiliation(s)
- J M Kramer
- Laboratory of Enteric Pathogens, Central Public Health Laboratory, Colindale, London, UK.
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48
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Abstract
Nidogen (entactin) can form a ternary complex with type IV collagen and laminin and is thought to play a critical role in basement membrane assembly. We show that the Caenorhabditis elegans nidogen homologue nid-1 generates three isoforms that differ in numbers of rod domain endothelial growth factor repeats and are differentially expressed during development. NID-1 appears at the start of embryonic morphogenesis associated with muscle cells and subsequently accumulates on pharyngeal, intestinal, and gonad primordia. In larvae and adults NID-1 is detected in most basement membranes but accumulates most strongly around the nerve ring and developing gonad. NID-1 is concentrated under dense bodies, at the edges of muscle quadrants, and on the sublateral nerves that run under muscles. Two deletions in nid-1 were isolated: cg119 is a molecular null, whereas cg118 produces truncated NID-1 missing the G2 collagen IV binding domain. Neither deletion causes overt abnormal phenotypes, except for mildly reduced fecundity. Truncated cg118 NID-1 shows wild-type localization, demonstrating that the G2 domain is not necessary for nidogen assembly. Both nid-1 mutants assemble type IV collagen in a completely wild-type pattern, demonstrating that nidogen is not essential for type IV collagen assembly into basement membranes.
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Affiliation(s)
- S H Kang
- Department of Cell and Molecular Biology, Northwestern University Medical School, Chicago, Illinois 60611, USA
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49
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Abstract
The hypothalamus is a well-known autonomic regulatory region of the brain involved in integrating several behaviors as well as cardiorespiratory activity. Our laboratory has shown that the caudal hypothalamus modulates the cardiorespiratory responses associated with exercise. In addition, other findings from this laboratory and others have implicated alterations in this same brain region in spontaneously hypertensive rats as contributing factors of the elevated levels of arterial pressure in hypertension. Several studies have revealed a gamma-amino-butyric acid (GABAergic) deficiency in the caudal hypothalamus of spontaneously hypertensive rats that contributes to the tonic disinhibition and overactivity of this pressor region. Because chronic exercise is able to increase cardiovascular health in the hypertensive rat, we hypothesized that exercise-induced caudal hypothalamic plasticity partially underlies the beneficial effects of physical activity. In this review we discuss initial findings from this lab that support this hypothesis. Our experiments demonstrate that chronic exercise alters gene expression and neuronal activity in the caudal hypothalamus of the spontaneously hypertensive rat. These findings describe a potential mechanism by which chronic exercise lowers blood pressure in the hypertensive individual.
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Affiliation(s)
- J M Kramer
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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50
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Abstract
Caenorhabditis elegans adult animals exhibit an inherent chirality of fiber orientation in the basal layer of the cuticle, as well as a naturally invariant but experimentally reversible handedness in the left-right (L-R) asymmetry of the body plan. We have examined the relationship between cuticle chirality and body handedness in normal and L-R reversed animals, using Roller (Rol) mutants and transmission electron microscopy to monitor cuticle properties. Rol phenotypes, several of which have been shown to result from mutations in cuticle collagen genes, are characterized by an invariant, allele-specific handedness in their direction of rolling. We show for several alleles that this direction is not affected by L-R reversal of the body plan. We further show, by electron microscopy, that the chiral orientation of cuticle fibers in animals with normal cuticle is not reversed by L-R body-plan reversal. We conclude that cuticle chirality must be established independently of body-plan handedness. The cues that establish cuticle chirality are still unknown, as are the causes for different rolling directions in different Roller mutants. We discuss the question of how cuticle chirality maintains its independence, and how the orientations of the fiber layers may be determined.
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Affiliation(s)
- D C Bergmann
- Department of MCD Biology, University of Colorado, Boulder 80309-0347, USA
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