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Striatal Cholinergic Interneuron Dysfunction in Dystonia Pathophysiology

肌张力障碍病理生理学中的纹状体胆碱能中间神经元功能障碍

基本信息

批准号：
10065199
负责人：
Jay Li
金额：
$ 2.06万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-01 至 2020-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10065199
关键词：
Ablation Adenovirus Vector Adolescent Adult Age Alleles Behavioral Cells Childhood Clinical Corpus striatum structure Data Defect Development Disease Dorsal Dyskinetic syndrome Dystonia Electrophysiology (science)Exhibits Functional disorder Genetic Goals Hyperactive behavior Immunohistochemistry Impairment Inherited Internal Ribosome Entry Site Interneuron function Interneurons Knockout Mice Lesion Limb structure Modeling Morphology Motor Movement Movement Disorders Mus Mutation Nerve Degeneration Neurodevelopmental Disorder Neurologic Neurons Pathogenesis Pharmaceutical Preparations Physicians Play Population Prosencephalon Proteins Publishing Research Ribosomal Protein S6 Rodent Model Role Scientist Signal Transduction Symptoms Synapses TOR1A gene Technology Testing Therapeutic TorsinA Treatment Efficacy Work Writing base behavioral phenotyping cholinergic cholinergic neuron conditional knockout designer receptors exclusively activated by designer drugs human disease motor disorder mouse genetics mouse model nervous system disorder novel prevent restoration selective expression skill acquisition skills tool

项目摘要

PROJECT SUMMARY DYT1 dystonia is the most common inherited form of dystonia, a common and disabling neurological movement disorder. Striatal dysfunction is thought to play a key role in dystonia pathophysiology, but it is unclear which neuronal classes are dysfunctional and drive abnormal movement. Morphologic and electrophysiologic abnormalities of striatal cholinergic interneurons (ChIs) have been observed in DYT1 mouse models, but many of these models do not exhibit motor dysfunction. This barrier to dystonia research was overcome when the Dauer lab generated an overtly symptomatic mouse model by conditionally knocking out torsinA from forebrain cholinergic and GABAergic neurons (including all striatal neurons) using Dlx5/6-Cre (“Dlx-CKO”). These mice exhibit dystonic-like twisting movements, selective degeneration of dorsal striatal ChIs, and morphologic and electrophysiologic changes in surviving ChIs. Clinically effective anti-muscarinic drugs suppress twisting movements in Dlx-CKO mice, establishing predictive validity and suggesting that aberrant function of remaining (non-degenerating) ChIs contributes to abnormal movement. To explore this possibility, I performed immunohistochemistry to determine intensity of phosphorylated ribosomal protein S6 (p-rpS6), a marker correlated with ChI activity. My preliminary data demonstrate that torsinA null ChIs exhibit elevated phosphorylated ribosomal protein S6 (p-rpS6), a finding consistent with altered ChI activity. Consistent with the hypothesis that abnormal activity of these cells contributes to dystonic-like movements, the p-rpS6 increase is selective to dorsal striatal (motor) ChIs and present only at behaviorally symptomatic ages. To examine whether abnormal ChI signaling is necessary for abnormal movement, I selectively lesioned these cells from the striatum of Dlx-CKO mice at symptomatic and pre-symptomatic ages and found that ChI ablation reverses and prevents abnormal twisting movements in Dlx-CKO mice, establishing their central role in dystonic-like symptoms. Based on my preliminary data and considerable published electrophysiological work implicating ChIs in dystonia pathophysiology, I hypothesize that ChIs are functionally abnormal in Dlx-CKO mice, and modulating ChI function is an effective therapeutic strategy. I will test this hypothesis with two aims: (1) defining the relationship between ChI activity and dystonic-like limb clasping using Designer Receptor Exclusively Activated by Designer Drugs (DREADD) technology and (2) determining if ChI-targeted genetic rescue of torsinA expression rescues neuropathologic and behavioral phenotypes in Dlx-CKO mice. The proposed studies will rigorously assess ChI dysfunction and therapeutic potential in one of the only overtly symptomatic rodent models of dystonia. Completion of the proposed work will further my writing, technical, and scientific skills and facilitate my development as a physician-scientist focused on neurologic disease.

项目概要 DYT1 肌张力障碍是肌张力障碍最常见的遗传形式，是一种常见且致残的神经运动紊乱。纹状体功能障碍被认为在肌张力障碍病理生理学中发挥着关键作用，但尚不清楚是哪个神经元类别功能失调并驱动异常运动。形态学和电生理学在 DYT1 小鼠模型中观察到纹状体胆碱能中间神经元 (ChIs) 异常，但许多这些模型中的一些没有表现出运动功能障碍。当肌张力障碍研究的这一障碍被克服时 Dauer 实验室通过有条件地敲除前脑中的 torsinA 来生成明显症状的小鼠模型使用 Dlx5/6-Cre (“Dlx-CKO”) 检测胆碱能和 GABA 能神经元（包括所有纹状体神经元）。这些老鼠表现出肌张力障碍样扭转运动、背侧纹状体 ChIs 的选择性变性以及形态和存活 ChIs 的电生理变化。临床有效的抗毒蕈碱药物可抑制扭曲 Dlx-CKO 小鼠的运动，建立了预测有效性并表明剩余功能的异常（非退化）ChI 会导致异常运动。为了探索这种可能性，我执行了免疫组织化学测定磷酸化核糖体蛋白 S6 (p-rpS6)（一种标记物）的强度与 ChI 活性相关。我的初步数据表明，torsinA null ChIs 表现出升高磷酸化核糖体蛋白 S6 (p-rpS6)，这一发现与 ChI 活性改变一致。符合假设这些细胞的异常活动导致肌张力障碍样运动，p-rpS6 的增加是对背侧纹状体（运动）ChIs 具有选择性，并且仅出现在有行为症状的年龄。来检查是否异常的 ChI 信号传导对于异常运动是必要的，我选择性地损伤了纹状体中的这些细胞对有症状和症状前年龄的 Dlx-CKO 小鼠进行研究，发现 ChI 消融可逆转并预防 Dlx-CKO 小鼠的异常扭转运动，确定了它们在肌张力障碍样症状中的核心作用。基于我的初步数据和大量已发表的涉及肌张力障碍中 ChI 的电生理学工作病理生理学，我假设 Dlx-CKO 小鼠 ChI 功能异常，并且调节 ChI 功能是一种有效的治疗策略。我将通过两个目标来检验这个假设：（1）定义关系使用由设计者独家激活的设计受体在 ChI 活动和肌张力障碍样肢体夹紧之间进行比较药物 (DREADD) 技术和 (2) 确定 TorsinA 表达的 ChI 靶向基因拯救是否有效 Dlx-CKO 小鼠的神经病理学和行为表型。拟议的研究将严格评估 ChI 唯一有明显症状的肌张力障碍啮齿动物模型之一的功能障碍和治疗潜力。完成拟议的工作将提高我的写作、技术和科学技能，并促进我的作为一名专注于神经系统疾病的医师科学家的发展。