Oligodendroglial Dysfunction in C9orf72 ALS and FTD

C9orf72 ALS 和 FTD 中的少突胶质细胞功能障碍

基本信息

批准号：
9902556
负责人：
BRETT M. MORRISON
金额：
$ 59.74万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-08-01 至 2022-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9902556
关键词：
ALS patients Amyotrophic Lateral Sclerosis Animal Model Antisense Oligonucleotides Astrocytes Attenuated Bacterial Artificial Chromosomes Biological Models C9ORF72 Cell Differentiation process Cell Line Cell Nucleus Cell Proliferation Cell model Cell physiology Cells Clinical Coculture Techniques Data Defect Dementia Development Dipeptides Disease Disease Marker Event Exportins Failure Familial Amyotrophic Lateral Sclerosis Frontotemporal Dementia Functional disorder Future Genetic Grant Health Human In Vitro Injury Laboratories Lead Longevity Mediating Metabolic Methodology Microglia Modeling Motor Neurons Mus Mutation Nerve Degeneration Neuroglia Neurons Nuclear Pore Nuclear Pore Complex Proteins Oligodendroglia Pathologic Pathology Pathway interactions Patients Pharmacology Play Pore Proteins Process Proteins Publishing RNA Research Rodent Role Superoxide Dismutase Supporting Cell Symptoms Techniques Time Toxic effect Transgenic Mice Validation Viral Vector Western Blotting Work attenuation cell injury cell type drug action drug discovery experimental study frontotemporal lobar dementia-amyotrophic lateral sclerosis human disease in vivo induced pluripotent stem cell inhibitor/antagonist motor neuron degeneration mouse model mutant myelination neurotoxicity novel strategies novel therapeutics nucleocytoplasmic transport oligodendrocyte precursor overexpression patient subsets precursor cell restoration selective expression superoxide dismutase 1 tool transcription factor

项目摘要

Amyotrophic lateral sclerosis (ALS) is a progressive, fatal disease characterized clinically and pathologically by progressive weakness and degeneration of motor neurons. A subset of patients can also have frontotemporal dementia with cortex injury. Though the symptoms of ALS are due to neuron degeneration, extensive research has shown that support cells in the CNS, including microglia, astrocytes, and recently oligodendrocytes, contribute to motor neuron degeneration. Our lab and others have shown that oligodendrocytes degenerate in ALS and that dysfunctional oligodendrocytes contribute to motor neuron degeneration, perhaps through failure of metabolic support to neurons. Oligodendrocyte dysfunction has been found in sporadic ALS, but also familial ALS associated with mutations in superoxide dismutase. Importantly, research from our laboratory has shown that oligodendrocytes play a critical role in neurodegeneration in SOD1 mice, since removing mutant SOD1 specifically from oligodendrocyte precursor cells (OPCs) and oligodendrocytes significantly prolongs lifespan in this mouse model of ALS. In the last several years, many research groups have focused on the recently discovered hexanucleotide repeat expansions (HREs) in C9orf72, which is the most common cause of familial ALS and also a common cause of frontotemporal dementia. These studies have determined that the neurotoxicity is likely due to both RNA- and dipeptide repeats (DPR) protein-mediated events. The exact mechanism by which these events produce toxicity is unknown, but published work by our laboratory and others has demonstrated that nucleocytoplasmic transport and nuclear pore proteins are disrupted in neurons expressing C9orf72HREs and restoration of this critical cell function leads to attenuation of neuronal toxicity. To date, there has been only one study on the role of C9orf72HREs in oligodendrocytes. In this proposal, we will thoroughly investigate the role of C9orf72HREs in OPCs and oligodendrocytes and their contribution to cellular dysfunction and degeneration in cellular and mouse models. We hypothesize that oligodendrocytes are dysfunctional in C9orf72 ALS and that alterations of nucleocytoplasmic transport lead to oligodendrocyte injury and reduced capacity for OPC differentiation. Specifically we propose to determine whether there is oligodendrocyte degeneration and OPC proliferation in ALS patients, and animal models with C9orf72 HREs. Our preliminary studies suggest C9orf72 is highly expressed in oligodendrocytes, which are dysfunctional in C9orf72 patients. We will then determine whether OPCs fail to differentiate and/or oligodendrocytes degenerate in C9orf72 ALS due to direct effect of repeat expansion on oligodendrocytes or an indirect effect from neuronal toxicity. Using oligodendrocyte monocultures and co-cultures with neurons derived from C9orf72 iPS cells and C9BAC mice, along with appropriate controls, we will evaluate OPC and oligodendrocyte proliferation, differentiation, survival, myelination, and support of neurons. We will also evaluate the impact on oligodendrocytes in vivo through viral vectors expressing HREs selectively in oligodendrocytes or neurons. To better understand the mechanism of oligodendroglial injury, we will determine whether OPCs or oligodendrocytes have dysfunctional nucleocytoplasmic transport in ALS patients and C9orf72HREs BAC transgenic mice. Finally, in hopes of using these model systems to mitigate injury, we will determine whether dysfunctional nucleocytoplasmic transport in OPCs and oligodendrocytes can be attenuated through genetic and pharmacologic techniques, including antisense oligonucleotides and nuclear transport modulators.

肌萎缩侧索硬化症 (ALS) 是一种进行性、致命性疾病，其临床和病理特征为运动神经元进行性无力和退化。一部分患者也可能患有额颞叶伴有皮质损伤的痴呆。尽管 ALS 的症状是由于神经元变性引起的，但广泛的研究研究表明，中枢神经系统中的支持细胞，包括小胶质细胞、星形胶质细胞和最近的少突胶质细胞，导致运动神经元变性。我们的实验室和其他人已经表明少突胶质细胞在 ALS 和功能失调的少突胶质细胞可能通过衰竭导致运动神经元变性对神经元的代谢支持。少突胶质细胞功能障碍已在散发性 ALS 中发现，但在家族性 ALS 中也有发现 ALS 与超氧化物歧化酶突变有关。重要的是，我们实验室的研究表明少突胶质细胞在 SOD1 小鼠的神经变性中发挥着关键作用，因为去除了突变的 SOD1 特别是来自少突胶质细胞前体细胞 (OPC) 和少突胶质细胞，可显着延长寿命这个 ALS 小鼠模型。在过去的几年里，许多研究小组将重点放在了最近的研究上。在 C9orf72 中发现了六核苷酸重复扩增 (HRE)，这是家族性遗传的最常见原因 ALS 也是额颞叶痴呆的常见原因。这些研究已确定神经毒性可能是由 RNA 和二肽重复 (DPR) 蛋白介导的事件引起的。确切的这些事件产生毒性的机制尚不清楚，但我们实验室和其他人已经证明神经元中的核细胞质运输和核孔蛋白被破坏表达 C9orf72HRE 和恢复这一关键细胞功能会导致神经元毒性减弱。迄今为止，只有一项关于 C9orf72HRE 在少突胶质细胞中的作用的研究。在这个提案中，我们将彻底研究 C9orf72HRE 在 OPC 和少突胶质细胞中的作用及其对细胞和小鼠模型中的细胞功能障碍和变性。我们假设少突胶质细胞 C9orf72 ALS 功能失调，核质运输的改变导致少突胶质细胞损伤和 OPC 分化能力降低。具体来说，我们建议确定是否存在少突胶质细胞变性和OPC ALS 患者和具有 C9orf72 HRE 的动物模型中的增殖。我们的初步研究表明 C9orf72 在少突胶质细胞中高表达，而少突胶质细胞在 C9orf72 患者中功能失调。我们随后将确定 C9orf72 ALS 中 OPC 是否无法分化和/或少突胶质细胞退化重复扩增对少突胶质细胞的直接影响或神经元毒性的间接影响。使用少突胶质细胞单一培养物以及与来自 C9orf72 iPS 细胞和 C9BAC 的神经元共培养物小鼠，以及适当的对照，我们将评估 OPC 和少突胶质细胞的增殖、分化、神经元的存活、髓鞘形成和支持。我们还将评估对体内少突胶质细胞的影响通过在少突胶质细胞或神经元中选择性表达 HRE 的病毒载体。为了更好地理解少突胶质细胞损伤的机制，我们将确定OPCs或少突胶质细胞是否具有 ALS 患者和 C9orf72HREs BAC 转基因小鼠的核细胞质运输功能障碍。最后，为了利用这些模型系统来减轻伤害，我们将确定是否功能失调 OPC 和少突胶质细胞中的核细胞质转运可通过遗传和遗传因素减弱药理学技术，包括反义寡核苷酸和核转运调节剂。