Dystonia in a Timothy syndrome mouse model uncovers an interaction between Ca2+ and metabolism.

Abstract

The hypothesized cellular and molecular mechanisms underlying dystonia are broad and include mutations that perturb Ca2+ signaling, including those affecting voltage gated calcium channels (VGCC). In mice, pharmacological activation of neuronal L-type VGCCs induces dystonia in a dose dependent manner. Here we demonstrate that mice expressing a gain-of-function mutation in the L-type VGCC CaV1.2, associated with Timothy syndrome (TS), exhibit motor dysfunction consistent with dystonia. Although CaV1.2 is broadly expressed throughout peripheral tissues and across the brain, we establish that the dystonia-like behavior is driven by neuronal expression of the mutant calcium channel and observe an associated potential excitatory/inhibitory (E/I) imbalance. Because patients with TS have profound metabolic dysregulation, which is associated with some dystonias, we measured changes in circulating metabolites. The dystonia-like events are sensitive to perturbations in pyruvate metabolism, reminiscent of a subset of dystonias associated with pyruvate dysregulation. Our study provides insight into the potential convergence of previously established causes of dystonia, calcium signaling and metabolic homeostasis.