4-Phenylbutyrate attenuates the ER stress response and cyclic AMP accumulation in DYT1 dystonia cell models

PLoS One. 2014 Nov 7;9(11):e110086. doi: 10.1371/journal.pone.0110086. eCollection 2014.

Abstract

Dystonia is a neurological disorder in which sustained muscle contractions induce twisting and repetitive movements or abnormal posturing. DYT1 early-onset primary dystonia is the most common form of hereditary dystonia and is caused by deletion of a glutamic acid residue (302/303) near the carboxyl-terminus of encoded torsinA. TorsinA is localized primarily within the contiguous lumen of the endoplasmic reticulum (ER) and nuclear envelope (NE), and is hypothesized to function as a molecular chaperone and an important regulator of the ER stress-signaling pathway, but how the mutation in torsinA causes disease remains unclear. Multiple lines of evidence suggest that the clinical symptoms of dystonia result from abnormalities in dopamine (DA) signaling, and possibly involving its down-stream effector adenylate cyclase that produces the second messenger cyclic adenosine-3', 5'-monophosphate (cAMP). Here we find that mutation in torsinA induces ER stress, and inhibits the cyclic adenosine-3', 5'-monophosphate (cAMP) response to the adenylate cyclase agonist forskolin. Both defective mechanins are corrected by the small molecule 4-phenylbutyrate (4-PBA) that alleviates ER stress. Our results link torsinA, the ER-stress-response, and cAMP-dependent signaling, and suggest 4-PBA could also be used in dystonia treatment. Other pharmacological agents known to modulate the cAMP cascade, and ER stress may also be therapeutic in dystonia patients and can be tested in the models described here, thus supplementing current efforts centered on the dopamine pathway.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cell Line
  • Cyclic AMP / metabolism*
  • Down-Regulation / drug effects
  • Dystonia Musculorum Deformans / drug therapy
  • Dystonia Musculorum Deformans / metabolism
  • Dystonia Musculorum Deformans / pathology*
  • Endoplasmic Reticulum Stress / drug effects*
  • Humans
  • Mice
  • Molecular Chaperones / metabolism
  • Phenylbutyrates / pharmacology*
  • Phenylbutyrates / therapeutic use
  • Signal Transduction / drug effects

Substances

  • Molecular Chaperones
  • Phenylbutyrates
  • TOR1A protein, human
  • 4-phenylbutyric acid
  • Cyclic AMP

Supplementary concepts

  • Dystonia musculorum deformans type 1