TorsinA hypofunction causes abnormal twisting movements and sensorimotor circuit neurodegeneration

Chun-Chi Liang, Lauren M. Tanabe, Stephanie Jou, Frank Chi, William T. Dauer
2014 Journal of Clinical Investigation  
Lack of a preclinical model of primary dystonia that exhibits dystonic-like twisting movements has stymied identification of the cellular and molecular underpinnings of the disease. The classical familial form of primary dystonia is caused by the DYT1 (ΔE) mutation in TOR1A, which encodes torsinA, AAA + ATPase resident in the lumen of the endoplasmic reticular/nuclear envelope. Here, we found that conditional deletion of Tor1a in the CNS (nestin-Cre Tor1a flox/-) or isolated CNS expression of
more » ... T1 mutant torsinA (nestin-Cre Tor1a flox/ΔE ) causes striking abnormal twisting movements. These animals developed perinuclear accumulation of ubiquitin and the E3 ubiquitin ligase HRD1 in discrete sensorimotor regions, followed by neurodegeneration that was substantially milder in nestin-Cre Tor1a flox/ΔE compared with nestin-Cre Tor1a flox/animals. Similar to the neurodevelopmental onset of DYT1 dystonia in humans, the behavioral and histopathological abnormalities emerged and became fixed during CNS maturation in the murine models. Our results establish a genetic model of primary dystonia that is overtly symptomatic, and link torsinA hypofunction to neurodegeneration and abnormal twisting movements. These findings provide a cellular and molecular framework for how impaired torsinA function selectively disrupts neural circuits and raise the possibility that discrete foci of neurodegeneration may contribute to the pathogenesis of DYT1 dystonia. Conflict of interest: The authors have declared that no conflict of interest exists. Citation for this article:
doi:10.1172/jci72830 pmid:24937429 pmcid:PMC4071385 fatcat:m3cz6cl4h5az3ezlkqepiy7d7e