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.
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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

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Figure 3

Generation of Pnkd-transgenic and -KO mice.

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Generation of Pnkd-transgenic and -KO mice. (A) 2 human mutations (A...
(A) 2 human mutations (A7V and A9V) were introduced into the BAC containing Pnkd. 62 kb of flanking sequence 5′ of the ATG start site is present in the BAC and is expected to contain all of the cis-acting regulatory elements leading to expression in a pattern faithful to the endogenous alleles. An internal ribosome entry site (IRES) followed by an enhanced red fluorescent protein gene (IRES/DsRed) was introduced into the 3′ UTR of the Pnkd gene. The original BAC without mutations was used for generation of Pnkd WT-Tg mice. (B) Southern blot analyses of mutant and WT-Tg mice. (C) Western blot analyses of brain extracts from mut-Tg and WT-Tg mice with C-terminal antibody. Tubulin was used as loading control. (D) Pnkd-KO mice. A short homologous arm upstream of exon 5 and a long homologous arm downstream of exon 9 were amplified and subcloned into the pMCIDT-A PGKNeo vector to replace 1.5 kb of genomic Pnkd DNA (including exons 5–9) with a neomycin resistance gene. (E) Genotype analyses of Pnkd-KO mice by RT-PCR. (F) Western blot analyses of mut-Tg and KO mice using C-terminal antibody. Tubulin was used as loading control. *Pnkd-L (~47 kDa); **Pnkd-M (~40 kDa).