Mechanisms of NLRP3 inflammasome activity in Parkinson's disease

NLRP3炎症小体活性在帕金森病中的机制

基本信息

批准号：
9760205
负责人：
Katharine M von Herrmann
金额：
$ 3.55万
依托单位：
DARTMOUTH COLLEGE
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-04-01 至 2020-05-03
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9760205
关键词：
Address Affect Age Aging Animal Model Animals Apoptosis Autopsy Biochemical Biological Models Cell Death Cell Line Cell model Cells Cellular Stress DNA Sequence Alteration Data Development Disease Disease Progression Dopamine Dopaminergic Cell Early Diagnosis Engineering Event Foundations Functional disorder Future Generations Genes Genetic Engineering Genetic Polymorphism Genetic Variation Heat shock proteins Histologic Human Immune Impairment Individual Inflammasome Inflammation Inflammatory Lewy Bodies Light Measures Microglia Mitochondria Modeling Molecular Multiprotein Complexes Mus Mutation Nerve Degeneration Neurodegenerative Disorders Neurogenic Inflammation Neuroglia Neurons Parkinson Disease Parkinsonian Disorders Pathogenesis Pathologic Pathology Pathway interactions Patients Prevention Process Proteins Reactive Oxygen Species Reporting Risk Scientist Single Nucleotide Polymorphism Stress Substantia nigra structure Testing Therapeutic Tissues Variant age related neurodegeneration age related neuroinflammation aged alpha synuclein cohort design dopaminergic neuron exome sequencing gain of function immunoreactivity longitudinal analysis misfolded protein motor impairment motor symptom mouse model neuroinflammation neuron loss new therapeutic target novel pars compacta prevent progression marker protein aggregate response synucleinopathy training opportunity

项目摘要

Parkinson’s disease (PD) is a progressive, neurodegenerative disorder characterized by debilitating motor symptoms. PD progression is characterized by loss of dopaminergic (DA) neurons in the substantia nigra pars compacta and accumulation of alpha-synuclein immunoreactive protein aggregates. PD has long been associated with neuroinflammation but it is not clear how PD-associated neuroinflammation is related to neuronal cell death. While a small percentage of PD cases can be attributed to genetic mutations, the molecular mechanisms underlying the initiation and progression of the more common sporadic form of PD are currently not well understood. The NLRP3 inflammasome is a multi-protein complex capable of initiating inflammation in response to cellular stress, including PD-associated factors such as reactive oxygen species and pathologically misfolded proteins. NLRP3 activity is best characterized in innate immune cells and microglia but our recent studies have identified elevated levels of NLRP3 expression in surviving DA neurons in mesencephalic tissues obtained from PD patients suggesting the possibility that DA neurons themselves may also be a cellular origin for inflammasome activity. In parallel studies, we identified an NLRP3 variant, single nucleotide polymorphism (SNP) rs7525979, to be associated with a decreased risk of classical PD using exome sequencing data obtained from the Parkinson’s Progression Markers Initiative. Our mechanistic studies in HEK293 cells suggest that rs7525979 inactivates NLRP3 but we do not know whether the SNP suppresses inflammasome activity in neurons. Additionally, we do not know if neuronal inflammasome activity is associated with neurodegeneration. We present two aims to directly address these outstanding questions. In our first aim, we will determine the impact of rs7525979 on NLRP3 inflammasome function in CNS cells including DA neurons. After genetically engineering a panel of CNS cell models, we will conduct studies to characterize classical indications of NLRP3 inflammasome activation, PD-associated neuronal pathologies including mitochondrial stress and misfolded protein aggregates, and measure levels of inflammasome-induced cell death, a process known as pyroptosis. In our second aim, we will determine if enhanced NLRP3 activity in DA neurons results in neuroinflammation and nigral cell loss in mice. To do so, we developed a DA neuron specific gain-of-function NLRP3 mouse model, and have already aged our first cohort of animals to 18 months observing longitudinal impairment of motor function. We plan to conduct a complete biochemical and histologic longitudinal analysis of the model to more fully understand the impact of enhanced NLRP3 inflammasome activity in DA neurons on both age-related neuroinflammation and neurodegeneration. Characterizing the functional impact of a neuroprotective genetic alteration in NLRP3 and determining whether neurogenic inflammasome activity can cause parkinsonism in mice will shed light on the underlying mechanisms of PD- associated neuroinflammation and help identify novel therapeutic targets for treatment and prevention of PD.

帕金森病 (PD) 是一种进行性神经退行性疾病，其特征是运动能力衰弱 PD 进展的特点是黑质部多巴胺能 (DA) 神经元的丧失。致密体和α-突触核蛋白免疫反应蛋白聚集体的积累长期以来一直被人们所关注。与神经炎症有关，但目前尚不清楚 PD 相关神经炎症如何与虽然一小部分 PD 病例可归因于基因突变，但更常见的散发性 PD 的发生和进展的分子机制是目前对NLRP3炎性体是一种能够启动的多蛋白复合物还没有很好的了解。细胞应激反应的炎症，包括活性氧等帕金森病相关因素 NLRP3 活性在先天免疫细胞中得到了最好的表征。但我们最近的研究发现存活的 DA 神经元中 NLRP3 表达水平升高在从 PD 患者获得的中脑组织中，这表明 DA 神经元本身可能也可能是炎症小体活动的细胞起源。在平行研究中，我们发现了 NLRP3 变体，单核苷酸多态性 (SNP) rs7525979，与使用药物降低经典 PD 风险相关从帕金森病进展标记计划获得的外显子组测序数据我们的机制研究。 HEK293 细胞中的 rs7525979 使 NLRP3 失活，但我们不知道 SNP 是否抑制此外，我们不知道神经元炎症小体活动是否相关。我们提出两个目标来直接解决这些悬而未决的问题。我们将确定 rs7525979 对 CNS 细胞（包括 DA）中 NLRP3 炎性体功能的影响在对一组中枢神经系统细胞模型进行基因改造后，我们将进行研究来表征。 NLRP3 炎症小体激活的经典适应症、PD 相关神经元病理包括线粒体应激和错误折叠的蛋白质聚集体，并测量炎症小体诱导细胞的水平在我们的第二个目标中，我们将确定 DA 中的 NLRP3 活性是否增强。神经元会导致小鼠神经炎症和黑质细胞损失，为此，我们开发了一种 DA 神经元特异性的药物。功能获得性 NLRP3 小鼠模型，并且我们的第一批动物已经老化至 18 个月我们计划进行完整的生化和组织学观察，观察运动功能的纵向损伤。对模型进行纵向分析，以更全面地了解增强型 NLRP3 炎性体的影响 DA 神经元对与年龄相关的神经炎症和神经变性的活性。 NLRP3 神经保护性基因改变的功能影响并确定是否神经源性炎症小体活动可导致小鼠帕金森病，这将揭示 PD 的潜在机制相关的神经炎症，并帮助确定治疗和预防 PD 的新治疗靶点。