Developing RNAi therapy For DYT1 dystonia

DYT1 dystonia is an early onset central nervous system-based movement disorder characterized by uncontrolled sustained muscle contractions that can lead to debilitating abnormal postures. Though a genetic mutation in the gene TOR1A is responsible for most DYT1 cases, the low penetrance of the disease implicates additional genetic and environmental modifiers. Current therapeutic options for DYT1 dystonia are limited to symptomatic treatments with variable effectiveness. Currently, the underlying pathogenesis of this disease and the role of torsinA (torA), the protein product of TOR1A, in the development of this disease have yet to be established. In the first part of this thesis we aimed to further understand the effects of the TOR1A mutation at the molecular, cellular and organismal level in order to identify disease associated biomarkers that can be later used to measure the effectiveness of novel therapies. We found that expression of mutant torsinA (torA(ΔE)) in a cellular and an animal model of DYT1 had no significant effect on global transcription, despite its interaction with nuclear envelope proteins. Recent research has unearthed a role for microRNAs (miRNAs) in neuronal development and maturation. Consequently we explored whether torA(ΔE) expression in murine neural tissue was associated with changes in miRNA expression in young DYT1 knockin (KI) mice. Since the primary sight of dysfunction is still being debated, we profiled miRNA expression of the two strongest candidates, the striatum and cerebellum, both of which have well established roles in the control and coordination of muscle movements. We have identified several microRNAs that were uniquely altered in either the striatum or cerebellum and further research will be conducted to determine their usability as disease biomarkers. Finally, we were unable to identify motor phenotypes in either a DYT1 (KI) mice or a novel DYT1 transgenic model in open field, rotarod or staircase forepaw reaching tests. In the second part of this thesis we aimed to develop and evaluate the safety and efficacy of viral therapeutic RNAi constructs for in DYT1 murine models. DYT1 is an