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自主的肌肉收缩，导致虚弱的扭转运动和 姿势。纹状体功能障碍与多种形式的肌张力障碍有关，包括特发性肌张力障碍， 遗传性肌张力障碍和医源性肌张力障碍。纹状体中的绝大多数神经元是GABA能棘突 投射神经元(SPN)。SPN表达D1R或D2多巴胺受体 (D2Rs)。D1Rs在直接通路SPN(DSPN)上表达，这些SPN投射到GPI促进运动。 D2Rs在间接途径SPN(ISPN)上表达，该SPN投射到外部苍白球(GPE)以抑制 有动静。对患者进行的遗传学、影像和生理学研究的一致结果表明 DSPN和iSPN的异常均可导致肌张力障碍的表达。尽管压倒性的 与肌张力障碍有关的纹状体功能障碍的证据，导致肌张力障碍的纹状体缺陷的确切性质 肌张力障碍是未知的。 针对肌张力障碍患者纹状体功能障碍的研究因缺乏动物实验而受阻 肌张力障碍运动与纹状体功能障碍有关的模型。要克服这一点 最近，我们建立了一种DOPA反应性肌张力障碍(DRD)的敲击小鼠模型。DRD鼠标 该菌株携带人类DRD导致酪氨酸羟化酶(ThDRD；DRD小鼠)的Q381K突变。就像 在人类失调的情况下，DRD小鼠表现出肌张力障碍的运动，这种运动在L-多巴给药后得到改善。 值得注意的是，纹状体DA神经传递，包括异常的D1R和D2R信号，在 肌张力障碍的表现。因此，这一新颖的老鼠模型提供了一个无与伦比的机会来理解 肌张力障碍dSPN和iSPN功能障碍的分子机制。 其具体目的是确定DRD小鼠dSPN和iSPN翻译组中细胞类型的特异性变化。 鉴于对肌张力障碍患者的纹状体功能障碍知之甚少，一种假设生成方法 全面介绍了dSPN和iSPN细胞类型的特定分子适应，以充分 破译肌张力障碍的发病机制。然而，理解细胞类型特定分子的一个主要挑战 肌张力障碍的改变是纹状体解剖的复杂性。因为dSPN和iSPN混合在一起 在整个纹状体，传统的全组织rna-seq不能用来描述细胞类型特异性。 异常现象。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小鼠的遗传识别的dSPN和iSPN中识别异常调控 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 肌张力障碍的细胞型特异性分子异常。