Dopamine dysregulation in a mouse model of paroxysmal nonkinesigenic dyskinesia
Hsien-yang Lee, … , Robert H. Edwards, Louis J. Ptácek
Hsien-yang Lee, … , Robert H. Edwards, Louis J. Ptácek
Published January 3, 2012
Citation Information: J Clin Invest. 2012;122(2):507-518. https://doi.org/10.1172/JCI58470.
View: Text | PDF
Research Article Neuroscience

Dopamine dysregulation in a mouse model of paroxysmal nonkinesigenic dyskinesia

Abstract

Paroxysmal nonkinesigenic dyskinesia (PNKD) is an autosomal dominant episodic movement disorder. Patients have episodes that last 1 to 4 hours and are precipitated by alcohol, coffee, and stress. Previous research has shown that mutations in an uncharacterized gene on chromosome 2q33–q35 (which is termed PNKD) are responsible for PNKD. Here, we report the generation of antibodies specific for the PNKD protein and show that it is widely expressed in the mouse brain, exclusively in neurons. One PNKD isoform is a membrane-associated protein. Transgenic mice carrying mutations in the mouse Pnkd locus equivalent to those found in patients with PNKD recapitulated the human PNKD phenotype. Staining for c-fos demonstrated that administration of alcohol or caffeine induced neuronal activity in the basal ganglia in these mice. They also showed nigrostriatal neurotransmission deficits that were manifested by reduced extracellular dopamine levels in the striatum and a proportional increase of dopamine release in response to caffeine and ethanol treatment. These findings support the hypothesis that the PNKD protein functions to modulate striatal neuro­transmitter release in response to stress and other precipitating factors.

Authors

Hsien-yang Lee, Junko Nakayama, Ying Xu, Xueliang Fan, Maha Karouani, Yiguo Shen, Emmanuel N. Pothos, Ellen J. Hess, Ying-Hui Fu, Robert H. Edwards, Louis J. Ptácek

×

Figure 1

Pnkd immunochemistry in mouse brain.

Options: View larger image (or click on image) Download as PowerPoint
Pnkd immunochemistry in mouse brain. (A) Oligopeptides used to produce P...
(A) Oligopeptides used to produce PNKD antibodies. Black rectangles represent exons shared by PNKD-L and PNKD-S; white rectangles represent exons shared by PNKD-L and PNKD-M; red rectangle represents the unique exon 1 of PNKD-M; blue rectangle represents the unique exon 3 of PNKD-S. Cysteines (underlined) were introduced in both oligopeptides to improve the coupling process. (B) Whole brain extracts on Western blots. The C-terminal antibody (1:5000 dilution) detected bands representing Pnkd-L (~47 kDa) and Pnkd-M (~40 kDa). The N-terminal antibody (1:500 dilution) detected bands representing Pnkd-L and Pnkd-S (~18 kDa). Pre-I, blots incubated with preimmune sera; Ag/Ab, PNKD antisera incubated with the oligopeptide against which they were raised; Ab, C- or N-terminal antisera only. (C) Double labeling in mice striatum with PNKD antibodies and either DARPP-32 (medium spiny neurons), ChAT (for cholinergic interneurons), or parvalbumin (Parv) (for GABAergic interneurons). (D) In striatum, Pnkd colocalizes with NeuN, a neuron-specific marker. (E) In striatum, Pnkd did not colocalize with oligodendrocyte-specific marker MBP. (F) Spinal cord cross section. Pnkd did not colocalize with astrocyte-specific marker GFAP. Original magnification, ×400.