Striatal cell-type specific molecular adaptations in a mouse model of dystonia

肌张力障碍小鼠模型中纹状体细胞类型特异性分子适应

• 批准号: 10057917
• 负责人: ELLEN J. HESS
• 金额: $ 41.61万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10057917
• 关键词: Affinity Chromatography; Anatomy; Animal Model; Basal Ganglia; Biochemical Pathway; Corpus striatum structure; Defect; Disease; Dopa-Responsive Dystonia; Dopamine D1 Receptor; Dopamine D2 Receptor; Dopamine Receptor; Dystonia; Exhibits; Foundations; Functional disorder; Genetic; Globus Pallidus; Human; Iatrogenesis; Image; Inherited; Knock-in Mouse; Knowledge; Levodopa; Light; Mediating; Messenger RNA; Microelectrodes; Molecular; Molecular Abnormality; Mouse Strains; Movement; Movement Disorders; Mus; Muscle Contraction; Mutation; Nature; Neuronal Dysfunction; Neurons; Operative Surgical Procedures; Parkinson Disease; Pathogenesis; Pathway interactions; Patients; Pattern; Physiological; Play; Positron-Emission Tomography; Posture; Process; Receptor Signaling; Research; Ribosomes; Role; Signal Pathway; Signal Transduction; Smooth Muscle; Structure; Time; Tissues; Translating; Tremor; Tyrosine 3-Monooxygenase; cell type; experimental study; improved; insight; mouse model; neurotransmission; new therapeutic target; novel; response; tool; transcriptome sequencing; translatome

Dystonia is characterized by involuntary muscle contractions that cause debilitating twisting movements and postures. Striatal dysfunction has been implicated in many forms of dystonia, including idiopathic dystonias, inherited dystonias and iatrogenic dystonias. The vast majority of neurons in the striatum are GABAergic spiny projection neurons (SPNs). SPNs express either D1 dopamine receptors (D1Rs) or D2 dopamine receptors (D2Rs). D1Rs are expressed on direct pathway SPNs (dSPNs) that project to the GPi to promote movement. D2Rs are expressed on indirect pathway SPNs (iSPNs) that project to the external pallidum (GPe) to inhibit movement. Convergent results from genetic, imaging and physiological studies in patients suggest that abnormalities of both dSPNs and iSPNs contribute to the expression of dystonia. Despite the overwhelming evidence implicating striatal dysfunction in dystonia, the precise nature of the striatal defects that give rise to dystonia are not known. Research focused on understanding striatal dysfunction in dystonia has been stymied by the lack of animal models with dystonic movements that are specifically associated with striatal dysfunction. To overcome this obstacle, we recently generated a knockin mouse model of DOPA-responsive dystonia (DRD). The DRD mouse strain carries the human DRD-causing Q381K mutation in tyrosine hydroxylase (ThDRD; DRD mice). Like the human disorder, DRD mice exhibit dystonic movements that that improve in response to L-DOPA administration. Notably, striatal DA neurotransmission, including abnormal D1R and D2R signaling, plays a central role in the expression of dystonia. Thus, this novel mouse model provides an unparalleled opportunity to understand the molecular mechanisms underlying dSPN and iSPN dysfunction in dystonia. The Specific Aim is to identify cell-type specific changes in the translatome of dSPNs and iSPNs in DRD mice. In light of how little is known about striatal dysfunction in dystonia, a hypothesis-generating approach that provides a comprehensive account of dSPN and iSPN cell-type specific molecular adaptations is needed to fully decipher the pathogenesis of dystonia. However, a major challenge to understanding cell-type specific molecular changes in dystonia is the complexity of striatal anatomy. Because dSPNs and iSPNs are intermingled throughout the striatum, traditional whole tissue RNA-seq is not useful for delineating cell-type specific abnormalities. Therefore, we will isolate translating ribosomes (Translating Ribosome Affinity Purification (TRAP)) from genetically identified dSPNs and iSPNs in normal and DRD mice to identify abnormally regulated processes and pathways associated with dystonia. This approach will provide unprecedented insight into the cell-type specific molecular abnormalities in dystonia.

肌张力障碍的特征是不随意的肌肉收缩，引起使人衰弱的扭转运动， 姿势纹状体功能障碍与许多形式的肌张力障碍有关，包括特发性肌张力障碍， 遗传性张力障碍和医源性张力障碍。纹状体中的绝大多数神经元是GABA能棘状神经元， 投射神经元（SPNs）。SPN表达D1多巴胺受体（D1 Rs）或D2多巴胺受体 （D2Rs）。D1 R在投射到GPi以促进运动的直接途径SPN（dSPN）上表达。 D2 R在间接途径SPN（iSPN）上表达，iSPN投射到外部苍白球（GPe）以抑制D2 R的表达。 运动对患者进行的遗传、成像和生理学研究的结果表明， dSPN和iSPN两者的异常都有助于肌张力障碍的表达。尽管绝大多 证据表明，纹状体功能障碍的肌张力障碍，确切的性质，纹状体缺陷，引起 肌张力障碍是未知的。 由于缺乏动物实验， 与纹状体功能障碍特别相关的张力障碍运动模型。为了克服这个 障碍，我们最近产生了多巴反应性肌张力障碍（DRD）的敲入小鼠模型。DRD鼠标 菌株在酪氨酸羟化酶中携带引起人DRD的Q381 K突变（ThDRD; DRD小鼠）。像 在人类疾病中，DRD小鼠表现出张力障碍运动，该运动响应于L-DOPA给药而改善。 值得注意的是，纹状体DA神经传递，包括异常的D1 R和D2 R信号传导，在神经系统的损伤中起着核心作用。 肌张力障碍的表达。因此，这种新的小鼠模型提供了一个无与伦比的机会，了解 肌张力障碍中dSPN和iSPN功能障碍的分子机制。 具体目的是鉴定DRD小鼠中dSPN和iSPN翻译组的细胞类型特异性变化。 鉴于对肌张力障碍中纹状体功能障碍知之甚少，一种产生假设的方法， 提供了dSPN和iSPN细胞类型特异性分子适应的全面说明， 解释肌张力障碍的发病机制然而，了解细胞类型特异性分子的一个重大挑战 肌张力障碍的变化是纹状体解剖的复杂性。由于dSPN和iSPN混合在一起， 在整个纹状体中，传统的全组织RNA-seq对于描绘细胞类型特异性 异常因此，我们将分离翻译核糖体（翻译核糖体亲和纯化 （TRAP））从正常和DRD小鼠中遗传鉴定的dSPN和iSPN中鉴定异常调节的 与肌张力障碍相关的过程和途径。这种方法将提供前所未有的洞察力， 肌张力障碍中的细胞类型特异性分子异常。