title: Short-lived recombinant adeno-associated virus transgene expression in dystrophic muscle is associated with oxidative damage to transgene mRNA.
abstract: Preclinical gene therapy strategies using recombinant adeno-associated virus (AAV) vectors in animal models of Duchenne muscular dystrophy have shown dramatic phenotype improvements, but long-lasting efficacy remains questionable. It is believed that in dystrophic muscles, transgene persistence is hampered, notably by the progressive loss of therapeutic vector genomes resulting from muscle fibers degeneration. Intracellular metabolic perturbations resulting from dystrophin deficiency could also be additional factors impacting on rAAV genomes and transgene mRNA molecular fate. In this study, we showed that rAAV genome loss is not the only cause of reduced transgene mRNA level and we assessed the contribution of transcriptional and post-transcriptional factors. We ruled out the implication of transgene silencing by epigenetic mechanisms and demonstrated that rAAV inhibition occurred mostly at the post-transcriptional level. Since Duchenne muscular dystrophy (DMD) physiopathology involves an elevated oxidative stress, we hypothesized that in dystrophic muscles, transgene mRNA could be damaged by oxidative stress. In the mouse and dog dystrophic models, we found that rAAV-derived mRNA oxidation was increased. Interestingly, when a high expression level of a therapeutic transgene is achieved, oxidation is less pronounced. These findings provide new insights into rAAV transductions in dystrophic muscles, which ultimately may help in the design of more effective clinical trials.
authors.affiliation: INSERM UMR 1089/Atlantic gene therapies , Nantes, France ; University of Nantes , Nantes, France ; Nantes University Hospital , Nantes, France.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Dupont
authors.affiliation: INSERM UMR 1089/Atlantic gene therapies , Nantes, France ; University of Nantes , Nantes, France ; Nantes University Hospital , Nantes, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Tournaire
authors.affiliation: GENETHON , Evry, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Georger
authors.affiliation: GENETHON , Evry, France.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Marolleau
authors.affiliation: GENETHON , Evry, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Jeanson-Leh
authors.affiliation: UMR INRA ONIRIS 703/Atlantic gene therapies , Nantes, France.
authors.forename: Mireille
authors.initials: M
authors.lastname: Ledevin
authors.affiliation: University of Nantes , Nantes, France ; Nantes University Hospital , Nantes, France ; INSERM UMR 1087/CNRS UMR 6291/L'Institut du Thorax , Nantes, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Lindenbaum
authors.affiliation: INSERM UMR 1089/Atlantic gene therapies , Nantes, France ; University of Nantes , Nantes, France ; Nantes University Hospital , Nantes, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Lecomte
authors.affiliation: INSERM UMR 1089/Atlantic gene therapies , Nantes, France ; University of Nantes , Nantes, France ; Nantes University Hospital , Nantes, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Cogné
authors.affiliation: UMR INRA ONIRIS 703/Atlantic gene therapies , Nantes, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Dubreil
authors.affiliation: UMR INRA ONIRIS 703/Atlantic gene therapies , Nantes, France.
authors.forename: Thibaut
authors.initials: T
authors.lastname: Larcher
authors.affiliation: GENETHON , Evry, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Gjata
authors.affiliation: GENETHON , Evry, France.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Van Wittenberghe
authors.affiliation: INSERM UMR 1089/Atlantic gene therapies , Nantes, France ; University of Nantes , Nantes, France ; Nantes University Hospital , Nantes, France ; GENETHON , Evry, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Le Guiner
authors.affiliation: INSERM UMR 1089/Atlantic gene therapies , Nantes, France ; University of Nantes , Nantes, France ; Nantes University Hospital , Nantes, France.
authors.forename: Magalie
authors.initials: M
authors.lastname: Penaud-Budloo
authors.affiliation: INSERM UMR 1089/Atlantic gene therapies , Nantes, France ; Department of Molecular Genetics and Microbiology, University of Florida College of Medicine , Gainesville, Florida, USA ; Center of Excellence for Regenerative Health Biotechnology, University of Florida College of Medicine , Gainesville, Florida, USA.
authors.forename: Richard O
authors.initials: RO
authors.lastname: Snyder
authors.affiliation: INSERM UMR 1089/Atlantic gene therapies , Nantes, France ; University of Nantes , Nantes, France ; Nantes University Hospital , Nantes, France ; Department of Molecular Genetics and Microbiology, University of Florida College of Medicine , Gainesville, Florida, USA.
authors.forename: Philippe
authors.initials: P
authors.lastname: Moullier
authors.affiliation: INSERM UMR 1089/Atlantic gene therapies , Nantes, France ; University of Nantes , Nantes, France ; Nantes University Hospital , Nantes, France.
authors.forename: Adrien
authors.initials: A
authors.lastname: Léger