Protein Aggregation and Inflammasome Signaling in Manganese Neurotoxicity

锰神经毒性中的蛋白质聚集和炎症小体信号转导

基本信息

批准号：
9275981
负责人：
Anumantha Gounder Kanthasamy
金额：
$ 32.89万
依托单位：
IOWA STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-06-01 至 2021-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9275981
关键词：
Address Affinity Agreement Alzheimer&apos s Disease Animal Model Astrocytes Binding Cell Culture Techniques Cells Chronic Complex Disease Encephalitis Endosomes Environment Functional disorder Goals Human Impairment Inflammasome Inflammatory Response Interleukin-1 beta Intervention Knockout Mice Link Manganese Mediating Metal Binding Site Metal exposure Metals Microglia Modeling Molecular Mus Nerve Degeneration Neurodegenerative Disorders Neurologic Neurons Outcome Parkinson Disease Pathogenesis Pathologic Pathway interactions Play Process Protein Sortings Proteins Recycling Research Role Sampling Signal Transduction Small Interfering RNA Sorting - Cell Movement Testing Transgenic Mice Up-Regulation Vesicle alpha synuclein brain tissue chronic neurologic disease divalent metal exosome extracellular genetic approach in vivo insight nervous system disorder neuroinflammation neuron loss neurotoxicity novel prion-like protein E protein aggregate protein aggregation protein complex public health relevance response trafficking

项目摘要

DESCRIPTION (provided by applicant): Metal exposure has increasingly been recognized as a potential environmental contributor to chronic neurodegenerative diseases including Parkinson's disease (PD) and Alzheimer's disease (AD). Chronic manganese (Mn) exposure has been implicated in Parkinson's-like neurological conditions in humans. Protein aggregation and its prion-like propagation are now considered the central pathophysiological mechanisms of many neurodegenerative diseases collectively known as proteinopathies. However, the role of metals in protein aggregation and the neurotoxicological mechanisms that drive degenerative processes are not well understood. α-Synuclein (αSyn) protein aggregation has been implicated in PD, and this protein features multiple divalent metal-binding motifs that have been suggested to play a role in αSyn's fibrillization and neurotoxicity. Since Mn shows affinity to the metal binding sites in αSyn, we have examined the effect of Mn on αSyn in neuronal models. Interestingly, we found that αSyn protected against Mn-induced neurotoxicity during early stages of Mn exposure, but prolonged Mn exposure promoted αSyn aggregation. In agreement with the emerging concept that aggregated proteins propagate cell-to-cell via exosomal release, we also observed enhanced release of exosomes containing αSyn into the extracellular environment during Mn exposure. Thus, our exciting finding of Mn-induced αSyn aggregation and release of exosomes with αSyn cargo prompts us to further characterize the cellular and molecular mechanisms of neurodegenerative processes in Mn neurotoxicity. Our proposal will test the novel hypothesis that Mn exposure promotes αSyn misfiling and impairs intracellular αSyn trafficking, thereby increasing the formation and release of exosomes containing αSyn protein aggregates, which subsequently trigger microglial activation through the NLRP3 inflammasome pathway in a PKCδ-dependent manner. Sustained activation of the PKCδ-dependent NLRP3 inflammasome pathway contributes to Mn neurotoxicity. Specific objectives of the proposal are: (i) to characterize the cellular mechanism of Mn-induced impairment in endosomal trafficking, retromer dysfunction and exosome release in cell culture and animal models of Mn neurotoxicity, (ii) to determine NLRP2/3 inflammasome neuroinflammatory signaling in microglia and astrocytes triggered by Mn-induced exosomal αSyn aggregates and to characterize the proinflammatory regulatory function of PKCδ in NLRP2/3 inflammasome activation in Mn neurotoxicity, and (iii), to examine the role of PKCδ in mediating the exosomal αSyn aggregate-induced proinflammatory response in animal models of Mn neurotoxicity and to confirm the presence of αSyn protein aggregation in Mn-exposed human brain tissues. Our integrated cellular and molecular approach to unraveling the formation and release of exosomal αSyn aggregates and their functional consequences on neuroinflammatory signaling in manganese metal neurotoxicity will provide novel mechanistic insights into environmentally-linked neurodegenerative disorders.

描述（由适用提供）：金属暴露已被认为是慢性神经退行性疾病的潜在环境贡献者，包括帕金森氏病（PD）（PD）和阿尔茨海默氏病（AD）。在人类的帕金森氏神经系统状况中，已实施了慢性锰（MN）暴露。现在，蛋白质聚集及其prion样的传播被认为是许多神经退行性疾病的中枢病理生理机制，共同被称为蛋白质病。然而，金属在蛋白质聚集中的作用和驱动退化过程的神经毒性机制尚不清楚。 α-syn（αSyn）蛋白聚集已在PD中实现，该蛋白具有多种二价金属结合基序，这些基序被认为在αSyn的纤维化和神经毒性中起着作用。由于MN显示了与αSyn中金属结合位点的亲和力，因此我们检查了MN对神经元模型中αSyn的影响。有趣的是，我们发现αSyn在MN暴露的早期阶段受到保护，免受MN诱导的神经毒性的影响，但延长MN暴露促进了αSyn聚集。与汇总蛋白通过外泌体释放传播细胞到细胞的新兴概念一致，我们还观察到在MN暴露期间，含有αSyn进入细胞外环境的外泌体释放增强。这是我们对MN诱导的αSyn聚集的激动人心的发现，并用αSyn货物释放外泌体促使我们进一步表征了MN神经毒性中神经退行性过程的细胞和分子机制。我们的建议将检验一个新的假设，即MN暴露会促进αSyn失误并损害细胞内的αSyn运输，从而增加含有αSyn蛋白聚集物的外泌体的形成和释放，随后通过PKC依赖性的pkc依赖性的方式触发NLRP3炎症体途径的小胶质细胞激活。 PKCδ依赖性NLRP3炎性途径的持续激活有助于MN神经毒性。该提案的具体目的是：（i）表征Mn诱导的损伤的细胞机制，内体贩运，逆转功能障碍和MN神经毒性的动物模型（II）的细胞培养和动物模型（II），以确定NLRP2/3炎症症神经毒性触发了触发型神经毒素 - 触发了触发了触发了触发的触发触发了触发的触发触发触发触发触发触发的微型触发触发触发触发触发触发触发触发的触发触发触发触发触发的触发触发触发物质。 αSyn聚集并表征PKCδ在NLRP2/3炎性体激活Mn神经毒性中的促炎调节功能，以及（iii），检验PKCΔ在介导外粒体αSy型诱导的促进性促进性毒性氧化物中的PKCΔ在介导的作用中，并确认了MN Neurot ot neuroxtiention inny neurotsy otny neuroxtions inty neuroxtions in neuroxtienty in neuro ofα暴露于Mn的人脑组织。我们的整合细胞和分子方法可以阐明外泌体αSyn聚集体的形成和释放及其对锰金属神经毒性中神经炎性信号传导的功能后果，将为环保神经退行性疾病提供新的机械洞察力。