Dynamic nuclear envelope phenotype in rats overexpressing mutated human torsinA protein.

A three-base-pair deletion in the human TOR1A gene is causative for the most common form of primary dystonia: the early-onset dystonia type 1 (DYT1 dystonia). The pathophysiological consequences of this mutation are still unknown. To study the pathology of the mutant torsinA (TOR1A) protein, we have generated a transgenic rat line that overexpresses the human mutant protein under the control of the human TOR1A promoter. This new animal model was phenotyped with several approaches, including behavioral tests and neuropathological analyses. Motor phenotype, cellular and ultrastructural key features of torsinA pathology were found in this new transgenic rat line, supporting that it can be used as a model system for investigating the disease's development. Analyses of mutant TOR1A protein expression in various brain regions also showed a dynamic expression pattern and a reversible nuclear envelope pathology. These findings suggest the differential vulnerabilities of distinct neuronal subpopulations. Furthermore, the reversibility of the nuclear envelope pathology might be a therapeutic target to treat the disease.