Molecular Phenotyping of Cortical Cell Types in ALS-Related Neurodegeneration

ALS 相关神经变性中皮质细胞类型的分子表型

• 批准号: 10745149
• 负责人: Eric F Schmidt
• 金额: $ 42.38万
• 依托单位: ROCKEFELLER UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10745149
• 关键词: ALS pathology; ALS patients; Address; Affinity Chromatography; Anatomy; Animal Model; Antioxidants; Autopsy; Biochemical; Biochemistry; Bioenergetics; Brain Stem; Candidate Disease Gene; Cell Nucleus; Cell Separation; Cells; Cerebral cortex; Clinical; Corticospinal Tracts; Data; Diagnosis; Disease; Disease Progression; Engineering; Etiology; Fluorescence; Functional disorder; Gene Expression; Gene Expression Profiling; Gene Expression Regulation; Genes; Goals; Grant; Innovative Therapy; Intervention; Label; Link; Maps; Measures; Metabolic; Mitochondria; Modeling; Molecular; Molecular Profiling; Motor Cortex; Motor Neuron Disease; Motor Neurons; Mus; Mutation; Nerve Degeneration; Nervous System; Neurons; Nuclear; Onset of illness; Oxidative Phosphorylation; Oxidative Stress; Pathologic Processes; Pathology; Pathway interactions; Patients; Pontine structure; Population; Pre-Clinical Model; Predisposition; Property; Proteins; Proteomics; Pyramidal Cells; Pyramidal Tracts; RNA-Binding Protein FUS; Research; Rest; Ribosomes; Role; Sorting; Spinal Cord; Symptoms; Techniques; Testing; Thalamic structure; Tissues; Transcript; Transgenic Mice; Translating; Up-Regulation; Viral; Viral Vector; Vulnerable Populations; Work; biological adaptation to stress; biomarker identification; candidate identification; cell cortex; cell type; cellular resilience; comparative; complex IV; disease-causing mutation; end stage disease; gain of function; human tissue; innovation; loss of function; metabolomics; molecular phenotype; multiple omics; neuropathology; new therapeutic target; novel; novel marker; pre-clinical; preclinical study; programs; resilience; response; translational framework

The combined degeneration of both “lower” motor neurons in the brainstem and spinal cord and “upper” motor neurons (UMNs) in the cerebral cortex is an important hallmark of ALS. Almost all cases of ALS are eventually fatal, and the rapid progression of the disease makes it particularly terrible, with over 80% of patients dying within five years of diagnosis. No cure exists for ALS and the only available treatments slow disease progression by merely a few months. Therefore, a great need exists for more effective and specific therapies that can stop or even reverse neurodegeneration. Innovation for such therapies will only arise from a better understanding of the molecular mechanisms underlying the pathological process, especially since most genes linked to ALS are ubiquitously expressed yet only specific populations of cells degenerate. Understanding why certain cells are uniquely vulnerable and mapping cell type specific pathways that are dysregulated during disease are crucial milestones. This has posed a considerable challenge for the spinal cord projecting UMNs since they are difficult to distinguish from other pyramidal cell types and are therefore often overlooked in preclinical studies. Because of this, the basis for their selective vulnerability to ALS-causing mutations has remained a mystery. The proposed study aims to overcome this by building on recent work that identified two highly similar yet molecularly distinct subpopulations of projection neurons in layer 5b of motor cortex, where UMNs reside. These populations have overlapping projections to pons, but non-overlapping projections to the spinal cord or thalamus. Examining these cells in preclinical models of ALS revealed that the corticospinal projecting neurons (CSTNs) were vulnerable to degeneration, while the corticopontine-only population (CPN) did not degenerate. The selective vulnerability of the CSTNs was likely due to dysregulation of mitochondrial function since a dramatic upregulation of genes related to oxidative phosphorylation and mitophagy was observed at symptomatic stages of disease. Aim 1 of this grant will employ an integrative multi-omics approach to address whether differences in the properties of mitochondria between CSTNs and CPNs drive differential responses to disease using a novel, viral-based strategy to isolate cell type specific mitochondria during disease progression in two preclinical ALS models, SOD1G93A and FUSP525L. Aim 2 focuses on dissecting the cellular role of identified candidate genes that are enriched in CSTNs and cell type-specific bioenergetic pathways, linking them to mitochondrial function and disease vulnerability. To increase the translational significance of this work, Aim 3 will leverage novel markers for CSTNs and CPNs for a detailed anatomical analysis of postmortem tissue from ALS patients to perform transcriptional profiling on cell type specific nuclei isolated by fluorescence activated nuclear sorting (FANS) from postmortem patient tissue. Results from this study will yield novel mechanisms underlying selective vulnerability of UMNs in ALS.

脑干和脊髓中“下”运动神经元和“上”运动神经元的联合变性 大脑皮层中的运动神经元（UMN）是ALS的重要标志。几乎所有的ALS病例都是 最终是致命的，疾病的快速发展使其特别可怕，超过80%的人 患者在确诊后五年内死亡。没有治愈ALS的方法，唯一可用的治疗方法缓慢 疾病的进展仅仅几个月。因此，非常需要更有效和更具体的 可以阻止甚至逆转神经退化的疗法。这种疗法的创新只会产生于 更好地了解病理过程的分子机制，特别是因为大多数 与ALS相关的基因普遍表达，但只有特定的细胞群退化。 了解为什么某些细胞是独特的脆弱性和映射细胞类型的特定途径， 疾病期间的失调是重要的里程碑。这对脊椎动物来说是一个巨大的挑战。 脊髓投射UMN，因为它们难以与其他锥体细胞类型区分，因此 在临床前研究中经常被忽视。正因为如此，他们对ALS的选择性脆弱性的基础， 突变仍然是一个谜。 这项拟议中的研究旨在通过建立在最近的工作基础上来克服这一点，这些工作发现了两个高度相似的 但在运动皮层的第5b层中的投射神经元的分子上不同的亚群，其中UMN驻留。 这些群体具有到脑桥的重叠投射，但是到脊髓或脊髓背侧的非重叠投射。 丘脑在ALS临床前模型中检查这些细胞，发现皮质脊髓投射神经元 （CSTNs）容易退化，而皮质桥蛋白（CPN）的人口没有退化。 CSTNs的选择性脆弱性可能是由于线粒体功能失调，因为 观察到氧化磷酸化和线粒体自噬相关基因的显著上调， 疾病的症状阶段。该补助金的目标1将采用综合多组学方法来解决 CSTN和CPN之间线粒体性质的差异是否驱动了对 在疾病进展过程中使用新的基于病毒的策略分离细胞类型特异性线粒体 在两个临床前ALS模型中，SOD1G93A和FUSP525L。目的2着重于剖析细胞的作用， 确定了富含CSTNs和细胞类型特异性生物能量途径的候选基因， 线粒体功能和疾病的脆弱性。为了增加这项工作的翻译意义， 目标3将利用CSTN和CPN的新标记物进行死后解剖的详细分析。 对通过荧光分离的细胞类型特异性核进行转录谱分析 活化核分选（FANS）。这项研究的结果将产生新的 ALS中UMN选择性脆弱性的潜在机制。