Sex-specific regulation of microRNAs in Alzheimer Disease

项目摘要 老年痴呆症在女性中比男性更普遍，但这种性别差异的生物学基础并不存在。 明白该提案的主要目的是了解17β-雌二醇（E2）如何调节microRNA (miR)在整个生命周期和阿尔茨海默病（AD）中的生物发生和稳定性。我们假设 老年人大脑中E2介导的miR表达失调导致阿尔茨海默病风险增加， 妇女提出的研究集中在了解雌激素如何调节这些miR，以获得一个更好的结果。 更好地了解他们在AD中的失调-特别是在女性中。这将解决我们的一个主要差距， 理解，因为E2如何影响miR生物合成途径的组成部分，以调节成熟的 尽管有几项研究表明，miR在细胞和/或年龄特异性方式中的表达水平是未知的， E2对多种器官系统中miR表达的时间和细胞特异性影响。我们之前的研究 表明E2处理改变了雌性大脑中miR亚组的表达水平， 调节这些miR的能力取决于年龄、脑区和E2剥夺的长度（即，时间后- 绝经期）。总体而言，目标1中的实验将检验E2差异介导 成熟miR稳定性取决于年龄和阿尔茨海默病。我们将使用miR降解试验， 确定年龄和/或E2是否影响miR降解速率，并使用蛋白质组学方法， 调节miR稳定性的顺式和反式作用因子。目标2将机械地解决如何选择 miR亚群可被E2转录后特异性调控。我们将检验hnRNP H与ERβ的结合降低了其与pri-miR转录物的结合，ERβ与BRCA 1相互作用， 促进DROSHA复合物组装，并且这些相互作用依赖于年龄和E2治疗。 目的3将确定年龄和E2对miR亚细胞定位的影响，并评估E2-miR的破坏。 阿尔茨海默病中miR介导的亚细胞定位。这一目标将检验E2促进 miR的亚细胞运输，从而影响miR功能。此外，我们将检验miR 亚细胞定位在整个生命周期中会发生变化，正常的年龄相关的亚细胞定位是 在老年痴呆症中被破坏。影响：了解E2在细胞中的基本分子信号通路 大脑老化将有助于推动治疗进展，并为阿尔茨海默氏症女性提供治疗策略 疾病

PROJECT SUMMARY Alzheimer’s Disease is more prevalent in women than men, yet a biological basis for this sex difference is not understood. The primary objective of this proposal is to understand how 17β-estradiol (E2) regulates microRNA (miR) biogenesis and stability across the lifespan and in Alzheimer’s Disease (AD). We hypothesize that dysregulation of E2-mediated miR expression in the aged brain leads to greater Alzheimer Disease risk in women. The studies proposed are focused on understanding how estrogens regulate these miRs to get a better understanding of their dysregulation in AD - specifically in women. This will address a major gap in our understanding because how E2 influences the components of the miR biogenesis pathway to regulate mature miR expression levels in a cell- and/or age-specific manner is unknown, despite several studies demonstrating temporal and cell-specific effects of E2 on miR expression in a variety of organ systems. Our prior studies demonstrated that E2 treatment altered the expression levels of a subset of miRs in the female brain, and the ability to regulate these miRs depended on age, brain region, and length of E2 deprivation (i.e., time post- menopause). Collectively the experiments in Aim 1 will test the hypothesis that E2 differentially mediates mature miR stability depending on age and in Alzheimer’s Disease. We will use miR degradation assays to determine whether age and/or E2 affect the rate of miR degradation and, using a proteomics approach, identify the cis- and trans-acting factors that regulate miR stability. Aim 2 will addresses mechanistically how a select subset of miRs could be specifically regulated by E2 post-transcription. We will test the hypothesis that hnRNP H binding to ERβ reduces its association with pri-miR transcripts, ERβ interacts with BRCA1 to differentially facilitate DROSHA complex assembly, and that these interactions are dependent on age and E2 treatment. Aim 3 will determine the effects of age and E2 on miR subcellular localization and assess disruption of E2- mediated miR subcellular localization in Alzheimer’s Disease. This aim will test the hypothesis that E2 facilitates subcellular trafficking of miRs, thereby impacting miR function. Moreover, we will test the hypothesis that miR subcellular localization changes across the lifespan and that normal age-related subcellular localization is disrupted in Alzheimer’s Disease. Impact: Understanding the basic molecular signaling pathways of E2 in the aging brain will help drive therapeutic advances and inform treatment strategies for women with Alzheimer’s Disease.