title: Silencing mutant SOD1 using RNAi protects against neurodegeneration and extends survival in an ALS model.
abstract: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease resulting in the selective death of motor neurons in the brain and spinal cord. Some familial cases of ALS are caused by dominant mutations in the gene encoding superoxide dismutase (SOD1). The emergence of interfering RNA (RNAi) for specific gene silencing could be therapeutically beneficial for the treatment of such dominantly inherited diseases. We generated a lentiviral vector to mediate expression of RNAi molecules specifically targeting the human SOD1 gene (SOD1). Injection of this vector into various muscle groups of mice engineered to overexpress a mutated form of human SOD1 (SOD1(G93A)) resulted in an efficient and specific reduction of SOD1 expression and improved survival of vulnerable motor neurons in the brainstem and spinal cord. Furthermore, SOD1 silencing mediated an improved motor performance in these animals, resulting in a considerable delay in the onset of ALS symptoms by more than 100% and an extension in survival by nearly 80% of their normal life span. These data are the first to show a substantial extension of survival in an animal model of a fatal, dominantly inherited neurodegenerative condition using RNAi and provide the highest therapeutic efficacy observed in this field to date.
authors.affiliation: Oxford Biomedica Ltd, Medawar Centre, The Oxford Science Park, Oxford, OX4 4GA, UK. s.ralph@oxfordbiomedica.co.uk
authors.forename: G Scott
authors.initials: GS
authors.lastname: Ralph
authors.forename: Pippa A
authors.initials: PA
authors.lastname: Radcliffe
authors.forename: Denise M
authors.initials: DM
authors.lastname: Day
authors.forename: Janine M
authors.initials: JM
authors.lastname: Carthy
authors.forename: Marie A
authors.initials: MA
authors.lastname: Leroux
authors.forename: Debbie C P
authors.initials: DC
authors.lastname: Lee
authors.forename: Liang-Fong
authors.initials: LF
authors.lastname: Wong
authors.forename: Lynsey G
authors.initials: LG
authors.lastname: Bilsland
authors.forename: Linda
authors.initials: L
authors.lastname: Greensmith
authors.forename: Susan M
authors.initials: SM
authors.lastname: Kingsman
authors.forename: Kyriacos A
authors.initials: KA
authors.lastname: Mitrophanous
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Mazarakis
authors.forename: Mimoun
authors.initials: M
authors.lastname: Azzouz
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics* / Q000628:therapy; D000818:Animals; D004195:Disease Models, Animal; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D009154:Mutation; D009410:Nerve Degeneration; D034622:RNA Interference; D034741:RNA, Small Interfering; D013482:Superoxide Dismutase / Q000235:genetics*; D015996:Survival Rate; D014162:Transfection
chemical_list: D034741:RNA, Small Interfering; C109415:SOD1 G93A protein; D013482:Superoxide Dismutase