A major challenge in understanding and treating dystonia is the limitation of current models for studying the disease. The dystonias are generally believed to represent chronic signaling dysfunctions in neurons within brain regions controlling movement, although characterizing subtle, dystonia-related disturbances in these cells at the molecular level has been difficult. Traditional approaches to model the disorder have relied on (1) peripheral patient cells (fibroblasts or lymphoblasts);(2) mutant mice;and/or (3) cultured cells bearing manipulations in proteins implicated in the disease process. While these strategies have value, there are limits to what they can reveal about effects of dystonia-related gene mutations on human neurons. Reprogramming patient somatic cells to induced pluripotent stem cells (iPSCs) which can be differentiated into neurons has become an increasingly common approach to modeling CNS disorders. Yet over time it has become clear that iPSCs can display substantial inter-individual variability which may confound identification of disease-specific phenotypes. Here we propose a strategy to develop a new human neuronal culture model of DYT1 dystonia that combines iPSCs reprogramming with gene targeting using transcription activator-like effector nucleases (TALENs). By using engineered TALENs to correct the DYT1 gene mutation in patient iPSCs, we will generate matched isogenic control lines from the same epigenetic background. As a first application of this model, we will perform transcriptional profiling with pathway analyses to identify functional networks that are perturbed in DYT1 iPSC-derived neurons compared to matched control cells. The outcome of this work will be a powerful new resource for probing neuron-specific deficits in DYT1 dystonia, with detailed expression profiling that will inform future studies of this model system.
Early onset (DYT1) dystonia is a crippling neurologic movement disorder. A major challenge in studying DYT1 is that the cells believed to be most affected by the disease mutation are neurons, which may be functionally distinct from the cell lines frequently used as experimental models. Here we propose to establish a new model system consisting of DYT1 patient-specific, induced pluripotent stem cells which can be differentiated into neurons, thereby facilitating new analyses of neuron-specific functional defects that may underlie this disease.
