RNA interference-mediated silencing of mutant superoxide dismutase rescues cyclosporin A-induced death in cultured neuroblastoma cells.
Amyotrophic lateral sclerosis (ALS) is a progressive and fatal neurodegenerative disorder resulting from selective death of motor neurons in the brain and spinal cord. In approximately 25% of familial ALS cases, the disease is caused by dominantly acting point mutations in the gene encoding cytosolic Cu,Zn superoxide dismutase (SOD1). In cell culture and in rodent models of ALS, mutant SOD1 proteins exhibit dose-dependent toxicity; thus, agents that reduce mutant protein expression would be powerful therapeutic tools. A wealth of recent evidence has demonstrated that the mechanism of RNA-mediated interference (RNAi) can be exploited to achieve potent and specific gene silencing in vitro and in vivo. We have evaluated the utility of RNAi for selective silencing of mutant SOD1 expression in cultured cells and have identified small interfering RNAs capable of specifically inhibiting expression of ALS-linked mutant, but not wild-type, SOD1. We have investigated the functional effects of RNAi-mediated silencing of mutant SOD1 in cultured murine neuroblastoma cells. In this model, stable expression of mutant, but not wild-type, human SOD1 sensitizes cells to cytotoxic stimuli. We find that silencing of mutant SOD1 protects these cells against cyclosporin A-induced cell death. These results demonstrate a positive physiological effect caused by RNAi-mediated silencing of a dominant disease allele. The present study further supports the therapeutic potential of RNAi-based methods for the treatment of inherited human diseases, including ALS.
Day Laboratory for Neuromuscular Research and High Throughput Screening Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
Michele M
MM
Maxwell
Piera
P
Pasinelli
Aleksey G
AG
Kazantsev
Robert H
RH
Brown
D001483:Base Sequence; D016923:Cell Death / Q000187:drug effects* / Q000235:genetics; D002470:Cell Survival / Q000187:drug effects; D016572:Cyclosporine / Q000633:toxicity*; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics; D020868:Gene Silencing; D006367:HeLa Cells; D006801:Humans; D016472:Motor Neuron Disease / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D009447:Neuroblastoma / Q000235:genetics* / Q000473:pathology; D034741:RNA, Small Interfering / Q000235:genetics*; D013482:Superoxide Dismutase / Q000235:genetics*; D000072105:Superoxide Dismutase-1; D014162:Transfection; D014407:Tumor Cells, Cultured
D017931:DNA Primers; D018076:DNA, Complementary; D034741:RNA, Small Interfering; C000606290:SOD1 protein, human; D016572:Cyclosporine; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1