title: Genomic integration of the full-length dystrophin coding sequence in Duchenne muscular dystrophy induced pluripotent stem cells.
abstract: The plasmid vectors that express the full-length human dystrophin coding sequence in human cells was developed. Dystrophin, the protein mutated in Duchenne muscular dystrophy, is extraordinarily large, providing challenges for cloning and plasmid production in Escherichia coli. The authors expressed dystrophin from the strong, widely expressed CAG promoter, along with co-transcribed luciferase and mCherry marker genes useful for tracking plasmid expression. Introns were added at the 3' and 5' ends of the dystrophin sequence to prevent translation in E. coli, resulting in improved plasmid yield. Stability and yield were further improved by employing a lower-copy number plasmid origin of replication. The dystrophin plasmids also carried an attB site recognized by phage phiC31 integrase, enabling the plasmids to be integrated into the human genome at preferred locations by phiC31 integrase. The authors demonstrated single-copy integration of plasmid DNA into the genome and production of human dystrophin in the human 293 cell line, as well as in induced pluripotent stem cells derived from a patient with Duchenne muscular dystrophy. Plasmid-mediated dystrophin expression was also demonstrated in mouse muscle. The dystrophin expression plasmids described here will be useful in cell and gene therapy studies aimed at ameliorating Duchenne muscular dystrophy.
authors.affiliation: Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Alfonso P
authors.initials: AP
authors.lastname: Farruggio
authors.affiliation: Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Mital S
authors.initials: MS
authors.lastname: Bhakta
authors.affiliation: Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Haley
authors.initials: H
authors.lastname: du Bois
authors.affiliation: Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Julia
authors.initials: J
authors.lastname: Ma
authors.affiliation: Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Michele
authors.initials: M
authors.lastname: P Calos
mesh_terms: D000818:Animals; D016189:Dystrophin / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D005786:Gene Expression Regulation; D015316:Genetic Therapy; D005822:Genetic Vectors; D023281:Genomics; D006801:Humans; D057026:Induced Pluripotent Stem Cells; D019426:Integrases / Q000235:genetics; D051379:Mice; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics* / Q000473:pathology
chemical_list: D016189:Dystrophin; D019426:Integrases
keywords: Duchenne muscular dystrophy; Dystrophin; Genomic integration; Human induced pluripotent stem cell; phiC31 integrase