title: Dp412e: a novel human embryonic dystrophin isoform induced by BMP4 in early differentiated cells.
abstract: BACKGROUND
  Duchenne muscular dystrophy (DMD) is a devastating X-linked recessive genetic myopathy. DMD physiopathology is still not fully understood and a prenatal onset is suspected but difficult to address.
  
  
  METHODS
  The bone morphogenetic protein 4 (BMP4) is a critical signaling molecule involved in mesoderm commitment. Human induced pluripotent stem cells (hiPSCs) from DMD and healthy individuals and human embryonic stem cells (hESCs) treated with BMP4 allowed us to model the early steps of myogenesis in normal and DMD contexts.
  
  
  RESULTS
  Unexpectedly, 72h following BMP4 treatment, a new long DMD transcript was detected in all tested hiPSCs and hESCs, at levels similar to that found in adult skeletal muscle. This novel transcript named "Dp412e" has a specific untranslated first exon which is conserved only in a sub-group of anthropoids including human. The corresponding novel dystrophin protein of 412-kiloDalton (kDa), characterized by an N-terminal-truncated actin-binding domain, was detected in normal BMP4-treated hiPSCs/hESCs and in embryoid bodies. Finally, using a phosphorodiamidate morpholino oligomer (PMO) targeting the DMD exon 53, we demonstrated the feasibility of exon skipping validation with this BMP4-inducible hiPSCs model.
  
  
  CONCLUSIONS
  In this study, the use of hiPSCs to analyze early phases of human development in normal and DMD contexts has led to the discovery of an embryonic 412 kDa dystrophin isoform. Deciphering the regulation process(es) and the function(s) associated to this new isoform can contribute to a better understanding of the DMD physiopathology and potential developmental defects. Moreover, the simple and robust BMP4-inducible model highlighted here, providing large amount of a long DMD transcript and the corresponding protein in only 3 days, is already well-adapted to high-throughput and high-content screening approaches. Therefore, availability of this powerful cell platform can accelerate the development, validation and improvement of DMD genetic therapies.
authors.affiliation: I-STEM, CECS, Génopôle-Campus 1, 5 rue Henri Desbruères, 91030 Evry, Cedex France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Massouridès
authors.affiliation: I-STEM, CECS, Génopôle-Campus 1, 5 rue Henri Desbruères, 91030 Evry, Cedex France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Polentes
authors.affiliation: CIRI, International Center for Infectiology Research, Université de Lyon, Lyon, France ; Inserm, U1111, Lyon, France ; CNRS, UMR5308, Lyon, France ; Ecole Normale Supérieure de Lyon, Lyon, France ; Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon, France.
authors.forename: Philippe-Emmanuel
authors.initials: PE
authors.lastname: Mangeot
authors.affiliation: UEVE U861, 91030 Evry, France ; Inserm U861, 91030 Evry, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Mournetas
authors.affiliation: Service de Biochimie et Génétique Moléculaire, HUPC Hôpital Cochin, Paris, France.
authors.forename: Juliette
authors.initials: J
authors.lastname: Nectoux
authors.affiliation: Service de Biochimie et Génétique Moléculaire, HUPC Hôpital Cochin, Paris, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Deburgrave
authors.affiliation: Service de Biochimie et Génétique Moléculaire, HUPC Hôpital Cochin, Paris, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Nusbaum
authors.affiliation: Service de Biochimie et Génétique Moléculaire, HUPC Hôpital Cochin, Paris, France.
authors.forename: France
authors.initials: F
authors.lastname: Leturcq
authors.affiliation: School of Biological Sciences, Royal Holloway-University of London, Surrey, TW20 0EX UK.
authors.forename: Linda
authors.initials: L
authors.lastname: Popplewell
authors.affiliation: School of Biological Sciences, Royal Holloway-University of London, Surrey, TW20 0EX UK.
authors.forename: George
authors.initials: G
authors.lastname: Dickson
authors.affiliation: Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205 USA.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Wein
authors.affiliation: Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205 USA.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Flanigan
authors.affiliation: UEVE U861, 91030 Evry, France ; Inserm U861, 91030 Evry, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Peschanski
authors.affiliation: IGBMC-CNRS UMR7104/Inserm U964, 67404 Illkirch, Cedex France.
authors.forename: Jamel
authors.initials: J
authors.lastname: Chelly
authors.affiliation: UEVE U861, 91030 Evry, France ; Inserm U861, 91030 Evry, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Pinset
keywords: Anthropoids; BMP4; Duchenne muscular dystrophy; Dystrophin; Embryonic; Exon skipping; Human; Isoform; hESCs; hiPSCs