The Mechanisms of Estrogen Receptor Beta Ligand Mediated Neuroprotection

 描述(申请人提供)：多发性硬化症(MS)是一种以中枢神经系统(CNS)炎症和脱髓鞘为特征的自身免疫性疾病。多发性硬化最常用的动物模型是实验性自身免疫性脑脊髓炎(EAE)。EAE是由Th1/Th17介导的免疫反应启动的，导致脱髓鞘和轴突损伤。目前的多发性硬化症治疗方法具有免疫调节作用，可降低多发性硬化症患者的复发率，但对残疾进展影响不大。有必要开发具有神经保护作用的新疗法，并了解其阻止残疾进展的机制。在神经退行性疾病模型中给予雌激素和雌激素受体(ER)特异性配体具有神经保护作用。具体地说，我们的实验室已经证明，ERβ配体的治疗通过提供临床疾病保护、保护神经元、防止脱髓鞘和促进重新髓鞘形成，在EAE期间具有神经保护作用。随着越来越多的证据表明ERβ在突触可塑性、改善记忆、脑发育和认知等方面发挥着重要作用，我们重点了解ERβ配体治疗神经保护的机制。最近，我们利用一种细胞特异性的方法，在中枢神经系统的细胞中建立ERβ的条件敲除，我们发现星形胶质细胞和神经元上ERβ的表达在介导ERβ配体治疗的神经保护作用中不起重要作用。相比之下，随后的一项研究报告说，少突胶质细胞可能起到了一定的作用，但其机制尚不清楚。本项目将重点研究ERβ配体治疗的神经保护作用是否通过中枢免疫细胞、小胶质细胞和树突状细胞(DC)介导。小胶质细胞和树突状细胞具有相似的表型和谱系特性，但它们位于不同的环境中。小胶质细胞是常驻的中枢神经系统免疫细胞，树突状细胞位于大脑边界附近，如脉络丛和血管周围空间。DC有一个特异的标记CD11c来研究它们，尽管最近有报道说在EAE过程中激活的小胶质细胞也表达CD11c。因此，用一个标记物研究这些细胞在体内的功能一直是很难实现的。在这项建议中，我们将利用DC标记CD11c进行细胞分选和 建立骨髓嵌合体以区分ERβ配体处理CD11c+小胶质细胞和DC的效果。此外，我们通过免疫荧光和共聚焦显微镜、流式细胞术和β表达分析，了解了每种细胞类型中ER-mR信号转导的潜在机制。

 DESCRIPTION (provided by applicant): Multiple sclerosis (MS) is an autoimmune disease characterized by inflammation and demyelination of the central nervous system (CNS). The most widely used animal model for MS is experimental autoimmune encephalomyelitis (EAE). EAE is initiated by Th1/Th17-mediated immune responses causing demyelination and axonal damage. Current MS treatments have immunomodulatory effects and reduce relapse rates in MS patients, but have modest effects on disability progression. There is a need to develop new treatments that are neuroprotective and understand their mechanisms to halt disability progression. Administration of estrogens and estrogen receptor (ER) specific-ligands in neurodegenerative disease models has neuroprotective effects. Specifically, our lab has shown that treatment with the ERβ-ligand is neuroprotective during EAE by providing clinical disease protection, preserving neurons, preventing demyelination and promoting remyelination. With increasing evidence that ERβ plays an important role in synaptic plasticity, improving memory, brain development and cognition, we focus on understanding the mechanisms of ERβ-ligand treatment on neuroprotection. Recently, using a cell specific approach by creating conditional knockouts (CKO) of ERβ in cells of the CNS, we shown that ERβ expression on astrocyte and neurons do not play an important role for mediating neuroprotective effects of ERβ-ligand treatment during EAE. In contrast, a subsequent study reported that oligodendrocytes may play a role, however, the mechanism remains unclear. This project will focus on investigating whether the neuroprotective effects of ERβ-ligand treatment are mediated through immune cells of the CNS, microglial cells and dendritic cells (DCs). Microglial cells and DCs share similar phenotypes and lineage properties, however, they are located in different environments. Microglial cells are resident CNS immune cells and DCs reside near the boundaries of the brain, such as the choroid plexus and perivascular space. DCs have a specific marker CD11c to study them, although, recently it has been reported that activated microglial cells also express CD11c during EAE. Therefore, studying the function of these cells in vivo using one marker has been difficult to achieve. In this proposal, we will utilize the DCs marker, CD11c, for cell sorting and creating bone marrow chimeras to distinguish the effect of ERβ-ligand treatment between CD11c+ microglial cells versus DCs. In addition, we understand the underlying mechanisms of ERβ signaling in each cell type through immunofluorescence and confocal microscopy, flow cytometry and mRNA expression analyses.