Alpha-synuclein regulates microglial activation through lipid mediators

描述(申请人提供)：帕金森氏病(PD)影响近3%的65岁以上的人，是美国第二常见的神经退行性疾病。近年来，人们越来越认识到炎症和小胶质细胞在帕金森病进展中的作用。1-突触核蛋白是一种在脑内广泛分布的140个氨基酸的蛋白质，与帕金森病和其他神经退行性疾病有关，但其在脑生理中的作用尚不清楚。我们和其他人的大量证据表明，1-突触核蛋白对脂质介导的信号转导和脑脂代谢具有深远的影响。脂质介导的信号转导是小胶质细胞激活调控途径的重要组成部分；然而，1-突触核蛋白通过调节脂质介导的信号转导调节小胶质细胞激活状态的作用尚不清楚。这一点很重要，因为我们最近发现了1-突触核蛋白和小胶质细胞激活状态之间的新联系。在这项建议中，我们将使用两种互补的方法来研究1-突触核蛋白在神经炎性反应中的作用，通过使用培养的小胶质细胞来确定这种异常表型的潜在机制，并将这些观察扩展到受到神经炎性损伤的完整小鼠，从而通过调节这些脂质介导的信号通路来实现。了解1-突触核蛋白及其突变形式如何影响小胶质细胞激活，将有助于深入了解帕金森病炎症反应的病理生理学。我们将解决我们的中心假设，即1-突触核蛋白的表达通过调节多个脂质介导的信号通路来调节小胶质细胞的激活，从而完成以下特定目标：特定目标1：确定wt和A53T 1-突触核蛋白表达调节脂质介导的小胶质细胞激活的程度特定目标2：解决wt和A53T 1-突触核蛋白表达在体内影响脂质介导的信号和小胶质细胞激活的程度本研究具有创新性，因为它研究了1-突触核蛋白及其突变形式(A53T)通过调节细胞脂质代谢的能力来调节小胶质细胞激活的新功能。我们期望，这些结果将确定1-突触核蛋白在促进前列腺素形成、PLD“和PLA2活性方面的关键作用，从而调节培养细胞和体内的下游脂质代谢和小胶质细胞的激活。这些结果将具有重要意义，因为它们将证明1-突触核蛋白在调节小胶质细胞激活从而调节脑炎症反应中发挥关键作用。这将为解决1-突触核蛋白及其突变形式在脑炎症反应中的作用提供必要的基本基础，扩大我们对1-突触核蛋白如何调节细胞脂质代谢，从而影响神经退行性疾病病理生理学的理解。公共卫生相关性我们建议的工作的相关性是，它研究了1-突触核蛋白通过调节脂质介导的小胶质细胞激活途径的能力，在调节脑神经炎症反应中的一种新功能。这很重要，因为：1)。1-突触核蛋白在脑内的功能不明确；1-突触核蛋白与大量神经退行性疾病的相关性；已知的炎症反应与这些神经退行性疾病的联系。该项目的结果将具有重要意义，因为它们将展示1-突触核蛋白在调节脑神经炎症反应中的关键作用，扩大我们对1-突触核蛋白如何调节细胞脂质代谢的理解，从而增加我们对1-突触核蛋白如何影响神经退行性疾病病理生理的理解。

DESCRIPTION (provided by applicant): Parkinson's disease (PD) affects nearly 3% of individuals over the age of 65 and is the second most common neurodegenerative disease in the United States. Recently, there is an increasing appreciation for the role of inflammation and microglia in the progression of PD. 1-Synuclein is a widely distributed 140 amino acid protein in brain associated with PD and other neurodegenerative disorders, but its role in brain physiology is poorly understood. There is ample evidence, by us and others, which demonstrates that 1-synuclein has a profound impact on lipid-mediated signal transduction and on brain lipid metabolism. Lipid-mediated signaling is a critical component of the regulatory pathway for microglial activation; however, the role of 1-synuclein in modulating microglia activation state via the regulation of lipid-mediated signal transduction is poorly defined. This is important because we have recently discovered a novel link between 1-synuclein and microglial activation state. We will use two complimentary approaches in this proposal to address the role of 1-synuclein in neuroinflammatory response via its regulation of these lipid-mediated signaling pathways by using cultured microglia to determine mechanisms underlying this aberrant phenotype and extending these observations to the intact mouse subjected to neuroinflammatory insult. Understanding how 1-synuclein and its mutant forms affects microglial activation will offer insight into the pathophysiology of the inflammatory response in PD. We will address our Central Hypothesis that 1-synuclein expression modulates microglia activation by regulating multiple lipid-mediated signaling pathways by completion of the following specific aims: Specific Aim 1: Determine the extent that wt and A53T 1-synuclein expression modulates lipid mediated microglial activation Specific Aim 2: Resolve the extent to which wt and A53T 1-synuclein expression impacts lipid mediated signaling and microglial activation in vivo The proposed work is innovative because it examines a novel function of 1-synuclein and its mutant form (A53T) in regulating microglial activation through its ability to modulate cellular lipid metabolism. It is our expectation that these results will identify a key role for 1-synuclein in facilitating prostaglandin formation, PLD "and PLA2 activity, thereby regulating downstream lipid metabolism and microglial activation, both in cultured cells and in vivo. These results will be significant because they will demonstrate a pivotal role for 1-synuclein "in regulating microglial activation and thus brain inflammatory response. This will provide the fundamental foundation required to address the role that 1-synuclein and its mutant forms have in brain inflammatory "response, extending our understanding of how 1-synuclein modulates cellular lipid metabolism, thereby impacting neurodegenerative disease pathophysiology. PUBLIC HEALTH RELEVANCE The relevance of our proposed work is that it examines a novel function of 1-synuclein in regulating brain neuroinflammatory response through its ability to modulate lipid-mediated microglial activation pathways. This is important because of: 1). the poorly defined function of 1-synuclein in the brain; 2). the association of 1- synuclein with a large number of neurodegenerative diseases; and 3). the known association of inflammatory response in these neurodegenerative diseases. Results from this project will be significant because they will demonstrate a pivotal role for 1-synuclein in regulating brain neuroinflammatory response, extending our understanding of how 1-synuclein modulates cellular lipid metabolism, thereby increasing our understanding of how 1-synuclein impacts neurodegenerative disease pathophysiology.