Pathophysiology of DYT1 dystonia: Targeted Mouse Models

DYT1 肌张力障碍的病理生理学：靶向小鼠模型

基本信息

批准号：
10710411
负责人：
YUQING LI
金额：
$ 36.29万
依托单位：
UNIVERSITY OF FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-28 至 2027-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10710411
关键词：
Acetylcholine Affect American Amino Acids Animal Model Antisense Oligonucleotides Artificial Intelligence Behavior Behavioral Binding Biochemical Brain Brain region Cells Characteristics Clustered Regularly Interspaced Short Palindromic Repeats Corpus striatum structure DRD2 gene DYT1 gene Development Disabled Persons Disease Dopamine Dopamine Receptor Dystonia Early Onset Dystonia Electrophysiology (science)Endoplasmic Reticulum Environment Exons Family Functional disorder Funding GAG Gene Genes Genetic Glutamates Goals Impairment Individual Interneurons Knock-in Knock-in Mouse Knockout Mice Knowledge Lead Limb structure Machine Learning Metabolism Modeling Molecular Chaperones Molecular Genetics Movement Movement Disorders Mus Muscle Contraction Neuronal Dysfunction Neurons Newborn Infant Nuclear Envelope Nucleotides Parkinson Disease Pathogenesis Pathway interactions Patients Penetrance Phenotype Play Posture Proteins Research Research Personnel Role Source Symptoms System TOR1A gene Techniques Testing TorsinA Tremor United States National Institutes of Health Wheelchairs Work autosome brain cell cell type cholinergic cholinergic neuron conditional knockout dopaminergic neuron early onset effective therapy gain of function in vivo interdisciplinary approach motor deficit mouse model network models neurochemistry novel protein folding protein function small hairpin RNA targeted treatment therapeutically effective

项目摘要

Dystonia is a movement disorder characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive, movements or postures. DYT1 early-onset generalized dystonia is the most common type among the genetic dystonias. Most of the individuals affected by DYT1 dystonia share a trinucleotide deletion (ΔGAG) located in exon 5 of DYT1 or TOR1A gene, leading to a loss of a glutamate amino acid residue for torsinA (torsinA∆E). The symptoms start from limbs and then become generalized. Affected individuals could be seriously disabled and need to use a wheelchair. Conditional knockout of torsinA in mice points to the involvement of multiple brain regions and cell types in the pathogenesis of DYT1 dystonia. These and other pathophysiological studies of DYT1 and other dystonias so far support a circuit or network model of dystonia pathogenesis. However, which brain region and neuronal types play a critical role in pathogenesis is unclear. Alterations of both the striatal dopaminergic and cholinergic systems appear to play a critical role in the pathophysiology of DYT1 dystonia. Dopaminergic modulation of striatal cholinergic interneurons (ChIs) is altered in multiple dystonia models that include DYT1 dystonia. Whether torsinA∆E in striatal ChIs has the cell-autonomous effect on striatal cholinergic dysfunction is not known. Preliminary studies of conditional knockin (KI) mouse models of DYT1 dystonia revealed dopaminergic and striatal medium spiny neurons (MSNs), but not ChIs, play a vital role in the pathogenesis of DYT1 dystonia. However, how torsinA∆E in MSNs and dopaminergic neurons lead to dystonia is unknown. These unknowns impede the progress in developing effective treatment for DYT1 patients, especially gene-based targeted therapy with CRISPR, antisense oligonucleotides, or small hairpin RNA. The broad, long-term objective of our research is 1) to determine the functional role of torsinA and the mechanism by which torsinA∆E leads to early-onset dystonia, 2) to develop novel and effective therapeutic treatment. The specific goal of this application is to generate and analyze five lines of conditional KI mice to understand the role of the striatal dopaminergic system and MSNs in the pathogenesis of DYT1 dystonia. We hypothesize that torsinA∆E in dopaminergic neurons and MSNs, but not ChIs, leads to abnormal firing of these neurons, decreased D1R and D2R in MSNs, altered striatal dopamine release, impaired corticostriatal LTD, altered direct and indirect pathways, and ultimately sustained muscle contractions and co-contractions that are characteristic of dystonia. Aim 1 will generate conditional MSN KI mice restricted to direct pathway, indirect pathway, or both and determine their phenotype. In Aim 2, we will introduce torsinA∆E specifically in dopaminergic neurons or ChIs and determine their dystonia-related phenotypes. The successful completion of the proposed research will significantly increase our understanding of the pathophysiology of DYT1 dystonia and aid the development of novel targeted treatments for dystonia patients.

肌张力障碍是一种运动障碍，其特征是持续或间歇性肌肉收缩，导致异常的、经常重复的动作或姿势是最常见的 DYT1 早发性全身性肌张力障碍。遗传性肌张力障碍中的常见类型大多数受 DYT1 肌张力障碍影响的个体都有一个共同点。位于 DYT1 或 TOR1A 基因外显子 5 的三核苷酸缺失 (ΔGAG)，导致谷氨酸丢失 torsinA 的氨基酸残基（torsinAΔE）症状从四肢开始，然后变得普遍。受影响的人可能会严重残疾并需要使用轮椅。在小鼠区域中，多种大脑和细胞类型参与 DYT1 肌张力障碍的发病机制。迄今为止对 DYT1 和其他肌张力障碍的这些和其他病理生理学研究支持回路或网络然而，哪些大脑区域和神经类型在肌张力障碍发病机制中发挥着关键作用。发病机制尚不清楚，纹状体多巴胺能和胆碱能系统的改变似乎起到了一定的作用。 DYT1 肌张力障碍的多巴胺能调节纹状体胆碱能的病理生理学中的关键作用。包括 DYT1 肌张力障碍在内的多种肌张力障碍模型中，中间神经元 (ChIs) 是否发生改变。纹状体 ChIs 对纹状体胆碱能功能障碍是否具有细胞自主作用尚不清楚。 DYT1 肌张力障碍的条件敲入 (KI) 小鼠模型显示多巴胺能和纹状体中等刺神经元 (MSN)，而不是 ChIs，在 DYT1 肌张力障碍的发病机制中发挥着至关重要的作用。 MSN 和多巴胺能神经元导致肌张力障碍的机制尚不清楚，这些未知因素阻碍了这一领域的进展。为 DYT1 患者开发有效的治疗方法，特别是基于 CRISPR 的基因靶向治疗，我们研究的广泛、长期目标是 1) 反义寡核苷酸或小发夹 RNA。确定torsinA的功能作用以及torsinAΔE导致早发性肌张力障碍的机制，2) 开发新颖且有效的治疗方法该应用程序的具体目标是产生和治疗。分析五系条件 KI 小鼠，了解纹状体多巴胺能系统和 MSN 的作用我们在 DYT1 肌张力障碍的发病机制中追踪了多巴胺能神经元和 MSN 中的 torsinAΔE，但是不是 ChIs，导致这些神经元异常放电，MSN 中 D1R 和 D2R 减少，纹状体改变多巴胺释放，皮质纹状体LTD受损，直接和间接途径改变，最终持续目标 1 会产生条件性肌肉收缩和共同收缩。 MSN KI 小鼠仅限于直接途径、间接途径或两者并确定其表型。我们将专门在多巴胺能神经元或 ChIs 中引入 torsinAΔE，并确定它们与肌张力障碍相关表型的成功完成将显着增加我们的理解。 DYT1 肌张力障碍的病理生理学研究，有助于开发针对肌张力障碍的新型靶向治疗方法患者。