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International Journal of Molecular... Apr 2022DYT1 dystonia is a debilitating neurological movement disorder that arises upon Torsin ATPase deficiency. Nuclear envelope (NE) blebs that contain FG-nucleoporins...
DYT1 dystonia is a debilitating neurological movement disorder that arises upon Torsin ATPase deficiency. Nuclear envelope (NE) blebs that contain FG-nucleoporins (FG-Nups) and K48-linked ubiquitin are the hallmark phenotype of Torsin manipulation across disease models of DYT1 dystonia. While the aberrant deposition of FG-Nups is caused by defective nuclear pore complex assembly, the source of K48-ubiquitylated proteins inside NE blebs is not known. Here, we demonstrate that the characteristic K48-ubiquitin accumulation inside blebs requires p97 activity. This activity is highly dependent on the p97 adaptor UBXD1. We show that p97 does not significantly depend on the Ufd1/Npl4 heterodimer to generate the K48-ubiquitylated proteins inside blebs, nor does inhibiting translation affect the ubiquitin sequestration in blebs. However, stimulating global ubiquitylation by heat shock greatly increases the amount of K48-ubiquitin sequestered inside blebs. These results suggest that blebs have an extraordinarily high capacity for sequestering ubiquitylated protein generated in a p97-dependent manner. The p97/UBXD1 axis is thus a major factor contributing to cellular DYT1 dystonia pathology and its modulation represents an unexplored potential for therapeutic development.
Topics: Adaptor Proteins, Vesicular Transport; Adenosine Triphosphatases; Autophagy-Related Proteins; Cell Membrane Structures; Dystonia; Dystonia Musculorum Deformans; Humans; Molecular Chaperones; Nuclear Envelope; Nuclear Pore Complex Proteins; Nuclear Proteins; Ubiquitin
PubMed: 35563018
DOI: 10.3390/ijms23094627 -
Human Molecular Genetics Mar 2022Dystonia is a disabling disease that manifests as prolonged involuntary twisting movements. DYT-THAP1 is an inherited form of isolated dystonia caused by mutations in...
Dystonia is a disabling disease that manifests as prolonged involuntary twisting movements. DYT-THAP1 is an inherited form of isolated dystonia caused by mutations in THAP1 encoding the transcription factor THAP1. The phe81leu (F81L) missense mutation is representative of a category of poorly understood mutations that do not occur on residues critical for DNA binding. Here, we demonstrate that the F81L mutation (THAP1F81L) impairs THAP1 transcriptional activity and disrupts CNS myelination. Strikingly, THAP1F81L exhibits normal DNA binding but causes a significantly reduced DNA binding of YY1, its transcriptional partner that also has an established role in oligodendrocyte lineage progression. Our results suggest a model of molecular pathogenesis whereby THAP1F81L normally binds DNA but is unable to efficiently organize an active transcription complex.
Topics: Apoptosis Regulatory Proteins; DNA-Binding Proteins; Dystonia; Dystonia Musculorum Deformans; Dystonic Disorders; Humans; Mutation; YY1 Transcription Factor
PubMed: 34686877
DOI: 10.1093/hmg/ddab310 -
Behavioural Brain Research Mar 2020DYT1 dystonia is an inherited movement disorder without obvious neurodegeneration. Multiple mutant mouse models exhibit motor deficits without overt "dystonic" symptoms...
DYT1 dystonia is an inherited movement disorder without obvious neurodegeneration. Multiple mutant mouse models exhibit motor deficits without overt "dystonic" symptoms and neurodegeneration. However, some mouse models do. Among the later models, the N-CKO mouse model, which has a heterozygous Tor1a/Dyt1 knockout (KO) in one allele and Nestin-cre-mediated conditional KO in the other, exhibits a severe lack of weight gain, neurodegeneration, overt "dystonic" symptoms, such as overt leg extension, weak walking, twisted hindpaw and stiff hindlimb, and complete infantile lethality. However, it is not clear if the overt dystonic symptoms were caused by the neurodegeneration in the dying N-CKO mice. Here, the effects of improved maternal care and nutrition during early life on the symptoms in N-CKO mice were analyzed by culling the litter and providing wet food to examine whether the overt dystonic symptoms and severe lack of weight gain are caused by malnutrition-related neurodegeneration. Although the N-CKO mice in this study replicated the severe lack of weight gain and overt "dystonic" symptoms during the lactation period regardless of culling at postnatal day zero or later, there was no significant difference in the brain astrocytes and apoptosis between the N-CKO and control mice. Moreover, more than half of the N-CKO mice with culling survived past the lactation period. The surviving adult N-CKO mice did not display overt "dystonic" symptoms, and in addition they still exhibited small body weight. The results suggest that the overt "dystonic" symptoms in the N-CKO mice were independent of prominent neurodegeneration, which negates the role of neurodegeneration in the pathogenesis of DYT1 dystonia.
Topics: Animal Culling; Animals; Caspase 3; Disease Models, Animal; Dystonia; Dystonia Musculorum Deformans; Female; Glial Fibrillary Acidic Protein; Lactation; Male; Mice; Mice, Knockout; Molecular Chaperones; Survival Rate; Weaning
PubMed: 31891745
DOI: 10.1016/j.bbr.2019.112451 -
Neurobiology of Disease Oct 2020Neuroinflammation plays a pathogenic role in neurodegenerative diseases and recent findings suggest that it may also be involved in X-linked Dystonia-Parkinsonism (XDP)...
Neuroinflammation plays a pathogenic role in neurodegenerative diseases and recent findings suggest that it may also be involved in X-linked Dystonia-Parkinsonism (XDP) pathogenesis. Previously, fibroblasts and neuronal stem cells derived from XDP patients demonstrated hypersensitivity to TNF-α, dysregulation in NFκB signaling, and an increase in several pro-inflammatory markers. However, the role of inflammatory processes in XDP patient brain remains unknown. Here we demonstrate that there is a significant increase in astrogliosis and microgliosis in human post-mortem XDP prefrontal cortex (PFC) compared to control. Furthermore, there is a significant increase in histone H3 citrullination (H3R2R8R17cit) with a concomitant increase in peptidylarginine deaminase 2 (PAD2) and 4 (PAD4), the enzymes catalyzing citrullination, in XDP post-mortem PFC. While there is a significant increase in myeloperoxidase (MPO) levels in XDP PFC, neutrophil elastase (NE) levels are not altered, suggesting that MPO may be released by activated microglia or reactive astrocytes in the brain. Similarly, there was an increase in H3R2R8R17cit, PAD2 and PAD4 levels in XDP-derived fibroblasts. Importantly, treatment of fibroblasts with Cl-amidine, a pan inhibitor of PAD enzymes, reduced histone H3 citrullination and pro-inflammatory chemokine expression, without affecting cell survival. Taken together, our results demonstrate that inflammation is increased in XDP post-mortem brain and fibroblasts and unveil a new epigenetic potential therapeutic target.
Topics: Adult; Aged; Aged, 80 and over; Astrocytes; Autopsy; Cell Survival; Chemokines; Citrullination; Dystonic Disorders; Female; Fibroblasts; Genetic Diseases, X-Linked; Gliosis; Histones; Humans; Inflammation; Leukocyte Elastase; Male; Microglia; Middle Aged; Ornithine; Peroxidase; Prefrontal Cortex; Protein-Arginine Deiminase Type 2; Protein-Arginine Deiminase Type 4
PubMed: 32739252
DOI: 10.1016/j.nbd.2020.105032 -
Movement Disorders : Official Journal... Dec 2021Acetylcholine-mediated transmission plays a central role in the impairment of corticostriatal synaptic activity and plasticity in multiple DYT1 mouse models. However,...
BACKGROUND
Acetylcholine-mediated transmission plays a central role in the impairment of corticostriatal synaptic activity and plasticity in multiple DYT1 mouse models. However, the nature of such alteration remains unclear.
OBJECTIVE
The aim of the present work was to characterize the mechanistic basis of cholinergic dysfunction in DYT1 dystonia to identify potential targets for pharmacological intervention.
METHODS
We utilized electrophysiology recordings, immunohistochemistry, enzymatic activity assays, and Western blotting techniques to analyze in detail the cholinergic machinery in the dorsal striatum of the Tor1a mouse model of DYT1 dystonia.
RESULTS
We found a significant increase in the vesicular acetylcholine transporter (VAChT) protein level, the protein responsible for loading acetylcholine (ACh) from the cytosol into synaptic vesicles, which indicates an altered cholinergic tone. Accordingly, in Tor1a mice we measured a robust elevation in basal ACh content coupled to a compensatory enhancement of acetylcholinesterase (AChE) enzymatic activity. Moreover, pharmacological activation of dopamine D2 receptors, which is expected to reduce ACh levels, caused an abnormal elevation in its content, as compared to controls. Patch-clamp recordings revealed a reduced effect of AChE inhibitors on cholinergic interneuron excitability, whereas muscarinic autoreceptor function was preserved. Finally, we tested the hypothesis that blockade of VAChT could restore corticostriatal long-term synaptic plasticity deficits. Vesamicol, a selective VAChT inhibitor, rescued a normal expression of synaptic plasticity.
CONCLUSIONS
Overall, our findings indicate that VAChT is a key player in the alterations of striatal plasticity and a novel target to normalize cholinergic dysfunction observed in DYT1 dystonia. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Topics: Acetylcholinesterase; Animals; Cholinergic Agents; Corpus Striatum; Dystonia; Dystonia Musculorum Deformans; Mice; Molecular Chaperones; Neuronal Plasticity; Vesicular Acetylcholine Transport Proteins
PubMed: 34173686
DOI: 10.1002/mds.28698 -
Journal of Voice : Official Journal of... Jan 2023To characterize the evolution of swallowing and voice in patients with X-linked dystonia parkinsonism (XDP).
OBJECTIVE
To characterize the evolution of swallowing and voice in patients with X-linked dystonia parkinsonism (XDP).
STUDY DESIGN
Retrospective case series.
METHODS
Retrospective review of 59 patients with XDP from January 2016 to January 2018. All patients underwent complete examinations and quality of life (QOL) surveys (Swallowing Quality of Life questionnaire [SWAL-QOL], Voice-Related Quality of Life [V-RQOL], and Voice Handicap Index [VHI]), and functional endoscopic examination of swallowing. We excluded patients with incomplete records or patients lost to follow-up. Univariate analysis was used to compare 2016 to 2018 Penetration-Aspiration Scale (PAS), SWAL-QOL, V-RQOL, and VHI scores.
RESULTS
Ten patients met the inclusion criteria. Nine patients had oromandibular dystonia. Voice-related measures significantly worsened with an increase in mean VHI from 81 to 109.9 (P = 0.026) and decrease in mean V-RQOL from 58 to 28 (P = 0.013). Vocal strain also significantly worsened 0.4 to 1.4 (P = 0.001). Mean PAS scores increased from 4.2 to 5.1 (P = 0.068) and mean SWAL-QOL decreased from 50.4 to 43.5 (P = 0.157). In the SWAL-QOL, the mean Eating Duration score worsened from 0.9 to 0.4 (P = 0.052) and Mental Health score declined from 10.1 to 6.1 (P = 0.077).
CONCLUSIONS
Both vocal strain and voice-related QOL measures considerably worsened over the 2-year interval in our limited group of XDP patients with no significant change in PAS scores or swallowing QOL. The findings demonstrated that the pace of disease affecting voice symptoms was different from swallowing symptoms in our study group and that changes in communication ability may be a more sensitive marker for disease progression than swallowing dysfunction.
Topics: Humans; Quality of Life; Retrospective Studies; Dystonia; Voice; Parkinsonian Disorders; Surveys and Questionnaires
PubMed: 33334627
DOI: 10.1016/j.jvoice.2020.11.014 -
Behavioural Brain Research Apr 2021DYT1 or DYT-TOR1A dystonia is early-onset, generalized dystonia. Most DYT1 dystonia patients have a heterozygous trinucleotide GAG deletion in DYT1 or TOR1A gene, with a...
DYT1 or DYT-TOR1A dystonia is early-onset, generalized dystonia. Most DYT1 dystonia patients have a heterozygous trinucleotide GAG deletion in DYT1 or TOR1A gene, with a loss of a glutamic acid residue of the protein torsinA. DYT1 dystonia patients show reduced striatal dopamine D2 receptor (D2R) binding activity. We previously reported reduced striatal D2R proteins and impaired corticostriatal plasticity in Dyt1 ΔGAG heterozygous knock-in (Dyt1 KI) mice. It remains unclear how the D2R reduction contributes to the pathogenesis of DYT1 dystonia. Recent knockout studies indicate that D2R on cholinergic interneurons (Chls) has a significant role in corticostriatal plasticity, while D2R on medium spiny neurons (MSNs) plays a minor role. To determine how reduced D2Rs on ChIs and MSNs affect motor performance, we generated ChI- or MSN-specific D2R conditional knockout mice (Drd2 ChKO or Drd2 sKO). The striatal ChIs in the Drd2 ChKO mice showed an increased firing frequency and impaired quinpirole-induced inhibition, suggesting a reduced D2R function on the ChIs. Drd2 ChKO mice had an age-dependent deficient performance on the beam-walking test similar to the Dyt1 KI mice. The Drd2 sKO mice, conversely, had a deficit on the rotarod but not the beam-walking test. Our findings suggest that D2Rs on Chls and MSNs have critical roles in motor control and balance. The similarity of the beam-walking deficit between the Drd2 ChKO and Dyt1 KI mice supports our earlier notion that D2R reduction on striatal ChIs contributes to the pathophysiology and the motor symptoms of DYT1 dystonia.
Topics: Animals; Behavior, Animal; Cholinergic Neurons; Corpus Striatum; Disease Models, Animal; Dystonia Musculorum Deformans; Female; Interneurons; Male; Mice; Mice, Knockout; Mice, Transgenic; Motor Activity; Postural Balance; Receptors, Dopamine D2
PubMed: 33476687
DOI: 10.1016/j.bbr.2021.113137 -
The Journal of Neuroscience : the... Mar 2021DYT1 dystonia is a hereditary neurologic movement disorder characterized by uncontrollable muscle contractions. It is caused by a heterozygous mutation in (), a gene...
DYT1 dystonia is a hereditary neurologic movement disorder characterized by uncontrollable muscle contractions. It is caused by a heterozygous mutation in (), a gene encoding a membrane-embedded ATPase. While animal models provide insights into disease mechanisms, significant species-dependent differences exist since animals with the identical heterozygous mutation fail to show pathology. Here, we model DYT1 by using human patient-specific cholinergic motor neurons (MNs) that are generated through either direct conversion of patients' skin fibroblasts or differentiation of induced pluripotent stem cells (iPSCs). These human MNs with the heterozygous mutation show reduced neurite length and branches, markedly thickened nuclear lamina, disrupted nuclear morphology, and impaired nucleocytoplasmic transport (NCT) of mRNAs and proteins, whereas they lack the perinuclear "blebs" that are often observed in animal models. Furthermore, we uncover that the nuclear lamina protein LMNB1 is upregulated in DYT1 cells and exhibits abnormal subcellular distribution in a cholinergic MNs-specific manner. Such dysregulation of LMNB1 can be recapitulated by either ectopic expression of the mutant gene or shRNA-mediated downregulation of endogenous in healthy control MNs. Interestingly, downregulation of LMNB1 can largely ameliorate all the cellular defects in DYT1 MNs. These results reveal the value of disease modeling with human patient-specific neurons and indicate that dysregulation of LMNB1, a crucial component of the nuclear lamina, may constitute a major molecular mechanism underlying DYT1 pathology. Inaccessibility to patient neurons greatly impedes our understanding of the pathologic mechanisms for dystonia. In this study, we employ reprogrammed human patient-specific motor neurons (MNs) to model DYT1, the most severe hereditary form of dystonia. Our results reveal disease-dependent deficits in nuclear morphology and nucleocytoplasmic transport (NCT). Most importantly, we further identify LMNB1 dysregulation as a major contributor to these deficits, uncovering a new pathologic mechanism for DYT1 dystonia.
Topics: Adolescent; Adult; Cell Culture Techniques; Cell Differentiation; Cells, Cultured; Cellular Reprogramming Techniques; Dystonia Musculorum Deformans; Female; Fibroblasts; Humans; Induced Pluripotent Stem Cells; Lamin Type B; Male; Middle Aged; Molecular Chaperones; Motor Neurons; Neural Stem Cells; Young Adult
PubMed: 33468570
DOI: 10.1523/JNEUROSCI.2507-20.2020 -
Annals of Clinical and Translational... Dec 2021The primary dystonia DYT6 is caused by mutations in the transcription factor Thanatos-associated protein 1 (THAP1). To understand THAP1's functions, we generated mice...
The primary dystonia DYT6 is caused by mutations in the transcription factor Thanatos-associated protein 1 (THAP1). To understand THAP1's functions, we generated mice lacking THAP1 in the nervous system. THAP1 loss causes locomotor deficits associated with transcriptional changes. Since many of the genes misregulated involve dopaminergic signaling, we pharmacologically challenged the two striatal canonical dopamine pathways: the direct, regulated by the D1 receptor, and the indirect, regulated by the D2 receptor. We discovered that depleting THAP1 specifically interferes with the D2 receptor responses, pointing to a selective misregulation of the indirect pathway in DYT6 with implications for pathogenesis and treatment.
Topics: Animals; DNA-Binding Proteins; Disease Models, Animal; Dopamine Agonists; Dopamine Antagonists; Dystonia Musculorum Deformans; Mice; Mice, Inbred C57BL; Mice, Knockout; Receptors, Dopamine D1; Receptors, Dopamine D2
PubMed: 34802187
DOI: 10.1002/acn3.51481 -
PLoS Computational Biology Sep 2021In behavioral learning, reward-related events are encoded into phasic dopamine (DA) signals in the brain. In particular, unexpected reward omission leads to a phasic...
In behavioral learning, reward-related events are encoded into phasic dopamine (DA) signals in the brain. In particular, unexpected reward omission leads to a phasic decrease in DA (DA dip) in the striatum, which triggers long-term potentiation (LTP) in DA D2 receptor (D2R)-expressing spiny-projection neurons (D2 SPNs). While this LTP is required for reward discrimination, it is unclear how such a short DA-dip signal (0.5-2 s) is transferred through intracellular signaling to the coincidence detector, adenylate cyclase (AC). In the present study, we built a computational model of D2 signaling to determine conditions for the DA-dip detection. The DA dip can be detected only if the basal DA signal sufficiently inhibits AC, and the DA-dip signal sufficiently disinhibits AC. We found that those two requirements were simultaneously satisfied only if two key molecules, D2R and regulators of G protein signaling (RGS) were balanced within a certain range; this balance has indeed been observed in experimental studies. We also found that high level of RGS was required for the detection of a 0.5-s short DA dip, and the analytical solutions for these requirements confirmed their universality. The imbalance between D2R and RGS is associated with schizophrenia and DYT1 dystonia, both of which are accompanied by abnormal striatal LTP. Our simulations suggest that D2 SPNs in patients with schizophrenia and DYT1 dystonia cannot detect short DA dips. We finally discussed that such psychiatric and movement disorders can be understood in terms of the imbalance between D2R and RGS.
Topics: Adenylyl Cyclases; Animals; Computational Biology; Corpus Striatum; Dopamine; Dystonia Musculorum Deformans; GTP-Binding Proteins; Humans; Learning; Long-Term Potentiation; Mental Disorders; Models, Neurological; Movement Disorders; Neurons; Receptors, Dopamine D2; Reward; Schizophrenia; Signal Transduction
PubMed: 34591840
DOI: 10.1371/journal.pcbi.1009364