Investigating selective regional and neuronal disease vulnerability in Spinocerebellar Ataxia Type 2

调查 2 型脊髓小脑共济失调的选择性区域和神经元疾病脆弱性

• 批准号: 10495190
• 负责人: Ashley Brooke Robbins
• 金额: $ 4.68万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10495190
• 关键词: Address; Affect; Age; Anterior; Atrophic; Autopsy; Bacterial Artificial Chromosomes; Behavioral; Behavioral Assay; Brain; Brain region; CAG repeat; Case Study; Cell Death; Cell Density; Cell Nucleus; Cell Survival; Cells; Cellular Stress; Cerebellar Diseases; Cerebellar degeneration; Cerebellum; Childhood; Clinical; Data; Degenerative Disorder; Development; Disease; Disease Progression; Exhibits; Functional disorder; Future; Gene Expression Profile; Gene Expression Profiling; Genes; Genetic; Genetic Transcription; Harvest; Hemagglutinin; Heterogeneity; Human; Immunoprecipitation; Individual; Inherited; Late-Onset Disorder; Length; Libraries; Link; Lobule; Maps; Messenger RNA; Methods; Modeling; Molecular; Morphology; Motor; Movement; Mus; Nerve Degeneration; Neuraxis; Neurodegenerative Disorders; Neurons; Nucleotides; Pathology; Pathway interactions; Patients; Pattern; Phenotype; Population; Preparation; Property; Proteins; Purkinje Cells; RNA; Recombinant adeno-associated virus (rAAV); Research; Resistance; Resolution; Ribosomes; Role; Speech; Structure; Supraoptic Vertical Ophthalmoplegia; Testing; Therapeutic; Therapeutic Intervention; Time; Tissue-Specific Gene Expression; Tissues; Transcript; Transgenes; Trinucleotide Repeat Expansion; Type 2 Spinocerebellar Ataxia; Validation; Variant; Work; cell type; differential expression; effective therapy; gain of function; knock-down; motor deficit; mouse model; mutant; neuronal circuitry; neurotoxic; normal aging; novel; novel therapeutic intervention; overexpression; promoter; resilience; response; ribosome profiling; single-cell RNA sequencing; spatiotemporal; targeted treatment; transcriptome; transcriptome sequencing; Address; Affect; Age; Anterior; Atrophic; Autopsy; Bacterial Artificial Chromosomes; Behavioral; Behavioral Assay; Brain; Brain region; CAG repeat; Case Study; Cell Death; Cell Density; Cell Nucleus; Cell Survival; Cells; Cellular Stress; Cerebellar Diseases; Cerebellar degeneration; Cerebellum; Childhood; Clinical; Data; Degenerative Disorder; Development; Disease; Disease Progression; Exhibits; Functional disorder; Future; Gene Expression Profile; Gene Expression Profiling; Genes; Genetic; Genetic Transcription; Harvest; Hemagglutinin; Heterogeneity; Human; Immunoprecipitation; Individual; Inherited; Late-Onset Disorder; Length; Libraries; Link; Lobule; Maps; Messenger RNA; Methods; Modeling; Molecular; Morphology; Motor; Movement; Mus; Nerve Degeneration; Neuraxis; Neurodegenerative Disorders; Neurons; Nucleotides; Pathology; Pathway interactions; Patients; Pattern; Phenotype; Population; Preparation; Property; Proteins; Purkinje Cells; RNA; Recombinant adeno-associated virus (rAAV); Research; Resistance; Resolution; Ribosomes; Role; Speech; Structure; Supraoptic Vertical Ophthalmoplegia; Testing; Therapeutic; Therapeutic Intervention; Time; Tissue-Specific Gene Expression; Tissues; Transcript; Transgenes; Trinucleotide Repeat Expansion; Type 2 Spinocerebellar Ataxia; Validation; Variant; Work; cell type; differential expression; effective therapy; gain of function; knock-down; motor deficit; mouse model; mutant; neuronal circuitry; neurotoxic; normal aging; novel; novel therapeutic intervention; overexpression; promoter; resilience; response; ribosome profiling; single-cell RNA sequencing; spatiotemporal; targeted treatment; transcriptome; transcriptome sequencing

PROJECT SUMMARY: Neurodegenerative disorders manifest selectively in particular neuronal populations and brain regions, through mechanisms we do not yet understand. Spinocerebellar Ataxia Type 2 (SCA2) is a fatal, hereditary neurodegenerative disorder caused by expansions in the CAG nucleotide repeat region of the ATXN2 gene, causing a gain-of-function ATXN2 protein with neurotoxic properties. While ATXN2 is expressed throughout the CNS, only a subset of brain structures and neurons are vulnerable to gross atrophy and cell death. The cerebellum is highly affected, resulting in the loss of voluntary movement, motor coordination, and speech difficulties in SCA2 patients. Across disease progression, there is pronounced cerebellar degeneration and selective loss of cerebellar Purkinje cells. Cerebellar degeneration occurs anterior to posterior, with the most posterior regions resistant to neurodegeneration. Multiple genetic and environmental insults also cause anterior to posterior cerebellar atrophy, suggesting that a conserved mechanism underlies the neurodegeneration gradient. To date, the cellular and molecular mechanisms underlying the variable cerebellar and Purkinje cell- specific vulnerability in SCA2 have not been investigated. I hypothesize that regional cerebellar vulnerability in SCA2 is modified by differential expression of neuroprotective pathways in response to cellular stress and disease. I will address this hypothesis in the following specific aims. In Aim 1, I will test whether Hspb1, a gene enriched in the posterior cerebellum, and previously identified as neuroprotective in other cerebellar degenerative disorders, can contribute to the protection of Purkinje cell loss in a mouse model of SCA2. If so, this will further support a conserved mechanism underlying the degenerative pattern and suggest common therapeutic avenues. In Aim 2A, I will identify novel neuroprotective pathways in a SCA2 model with the use of high throughput single-cell RNA-sequencing of the cerebellar transcriptome at fine temporal and spatial resolution. In Aim 2B, I will specifically address regional Purkinje cell vulnerability in SCA2 through the use of cell-type-specific ribosomal profiling to assess differential gene expression between disease-vulnerable and - resilient Purkinje cell populations. By comparing differential gene expression between the anterior and posterior cerebellum in both Aim 2A and Aim 2B, I will identify novel genetic modifiers of disease vulnerability for future validation. This study will be the first to characterize SCA2 degeneration and disease progression at a single- cell spatiotemporal resolution. As there is no effective treatment available for SCA2 patients, understanding the factors that protect against neurodegeneration and cell-type-specific contributions to disease pathology will help to better inform future therapeutic interventions.

项目摘要： 神经退行性疾病在特定的神经元种群和大脑区域中选择性地表现出来， 我们尚不理解的机制。棘脑脑性共济失调2型（SCA2）是致命的，遗传的 由ATXN2基因的CAG核苷酸重复区域的扩张引起的神经退行性疾病， 引起具有神经毒性特性的功能获得的ATXN2蛋白。而ATXN2在整个过程中表达 中枢神经系统，只有一部分脑结构和神经元容易受到萎缩和细胞死亡的影响。这 小脑受到高度影响，导致自愿运动，运动协调和语音的丧失 SCA2患者的困难。在疾病进展中，有明显的小脑变性和 小脑Purkinje细胞的选择性丧失。小脑变性发生在后方，最多 后区域对神经退行性的抗性。多种遗传和环境侮辱也会导致前部 在小脑后萎缩，表明保守的机制是神经变性的基础 坡度。迄今为止，可变小脑和Purkinje细胞的细胞和分子机制 SCA2中的特定漏洞尚未进行研究。我假设区域小脑脆弱性 在SCA2中，通过响应细胞应激的神经保护途径的差异表达来改变 和疾病。我将在以下特定目标中解决这一假设。在AIM 1中，我将测试HSPB1是否 富含后小脑的基因，以前在其他小脑中被鉴定为神经保护作用 退化性疾病可以在SCA2的小鼠模型中保护浦肯野细胞损失。如果是这样， 这将进一步支持退化模式下的保守机制，并提出共同 治疗途径。在AIM 2A中，我将使用SCA2模型中的新型神经保护途径使用 小脑转录组的高吞吐量单细胞RNA序列在临时和空间上 解决。在AIM 2B中，我将通过使用SCA2中的区域Purkinje细胞漏洞来解决 细胞型特异性核糖体分析，以评估疾病可造成的差异基因表达和 - 弹性Purkinje细胞种群。通过比较前后的差异基因表达 小脑在AIM 2A和AIM 2B中，我将确定疾病脆弱性的新型遗传修饰符 验证。这项研究将是第一个表征SCA2变性和疾病进展的一项。 细胞时空分辨率。由于没有适用于SCA2患者的有效治疗方法，因此了解 防止神经退行性变性和细胞类型对疾病病理的贡献的因素将有助于 更好地告知未来的治疗干预措施。