Epigenetic regulation of sexually divergent neuroinflammation with brain aging and Alzheimer's disease

性别分化神经炎症与大脑衰老和阿尔茨海默病的表观遗传调控

• 批准号: 10220837
• 负责人: Sarah Renee Ocanas
• 金额: $ 2.66万
• 依托单位: UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-16 至 2022-05-23
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10220837
• 关键词: Address; Adult; Affinity Chromatography; Age; Aging; Alzheimer' s Disease; Alzheimer' s disease model; Amyloid beta-Protein; Animals; Anti-Inflammatory Agents; Brain; Cell Nucleus; Centenarian; Characteristics; Chronic; Cognitive; Cognitive deficits; Cytosine; DNA; DNA Methylation; DNA Modification Process; Data; Data Set; Development; Epigenetic Process; Female; Future; Gene Expression; Genome; Gliosis; Goals; Hippocampus (Brain); Home; Human; Hyperactivity; Immunohistochemistry; Impaired cognition; Incidence; Inflammation; Inflammatory; Infusion procedures; Life; Messenger RNA; Methods; Methylation; Microglia; Modeling; Modification; Monitor; Mus; Nerve Degeneration; Neurodegenerative Disorders; Nucleic Acid Regulatory Sequences; Nucleic Acids; Pathologic; Pathway interactions; Pattern; Peptides; Phenotype; Physiological; Play; Predisposition; Process; Proteins; RNA; Regulation; Research Training; Ribosomes; Risk Factors; Rodent Model; Role; Sentinel; Sex Differences; Stimulus; Tamoxifen; Therapeutic Intervention; Transgenic Animals; Transgenic Model; Transgenic Organisms; Translating; Woman; abeta oligomer; age effect; age related; aged; aging brain; bisulfite sequencing; cell type; chemokine; cognitive testing; comparative; cytokine; epigenetic regulation; epigenome; epigenome editing; epigenomics; experimental study; genomic locus; insight; lateral ventricle; macrophage; male; neuroinflammation; neuropathology; neurotoxicity; novel; prevent; response; sex; therapeutic development; transcriptome; transcriptomics; whole genome

PROJECT SUMMARY/ABSTRACT Age and sex are the primary risk factors for developing Alzheimer’s disease (AD), with a higher incidence in women at all ages from 60-100 years old. Mechanisms underlying the cause of sex differences in AD are not well understood, preventing the development of sex-specific therapeutic interventions. Chronic, low-grade inflammation is characteristic of brain aging and neurodegeneration. As the sentinel macrophages of the CNS, microglia play an important role in sensing and responding to changes in the CNS milieu. Microglia monitor the CNS for foreign/’non-self’ and endogenous substances, serving both neuroprotective and neurodegenerative functions. Under normal physiological conditions, microglia retain a relatively quiescent, surveillance phenotype; however stimulation can polarize microglia to the pro-inflammatory M1 phenotype or anti-inflammatory M2 phenotype. Control of microglial phenotypic switching involves regulation of DNA modifications, principally methylation and hydroxymethylation of cytosines, which control genome accessibility and gene expression. Exuberant activation of microglial-specific inflammatory pathways with age in females and sexual divergence in DNA modifications with age point to an epigenetic role in sex differences in brain aging and neuroinflammation. However, paired epigenomic and transcriptomic studies have not been conducted in hippocampal microglia with age between sexes. To address this barrier to progress we developed microglial-specific, tamoxifen-inducible, transgenic NuTRAP models to allow isolation of nucleic acids (DNA & RNA) from lineage-traced microglia. In Aim 1, microglial-specific hippocampal changes in mC/hmC with aging will be examined by whole genome oxidative bisulfite sequencing (WGoxBS). Epigenomic data, and the paired transcriptomic data from the same animals will be used to determine the role of altered modification patterns in age-related changes in gene expression, enrichment of differential modifications in regulatory regions of the genome, and to identify genomic loci for future epigenome editing experiments. Although sexual divergence is documented in some current rodent models of AD, an acknowledged limitation in the field is that transgenic animals develop AD neuropathology at a young age, unlike sporadic AD, which occurs late in life. New AD models like amyloid-beta (Aβ) oligomer infusion allow for examination of AD-related Aβ neuropathology in the context of brain aging and sex effects. In Aim 2, we combine Aβ-oligomer infusion with our novel NuTRAP model to selectively analyze microglial-specific epigenomic and transcriptomic changes in the context of Aβ neurotoxicity. Further, immunohistochemistry and cytokine/chemokine panels are used readouts for gliosis, to assess the effect of aging on Aβ-induced microglial reactivity between sexes. If successful, these studies will provide insights into sexually divergent microglial function with aging and Aβ-related neuropathology and identify targets for development of sex-specific therapeutic interventions. Future studies will also use these findings to examine the regulators of sexual divergence with brain aging.

项目总结/摘要 年龄和性别是患阿尔茨海默病（AD）的主要危险因素，其中老年人的发病率较高。 60-100岁的所有年龄段的妇女。导致AD性别差异的潜在机制不是 很好地理解，防止性别特异性治疗干预措施的发展。慢性，低度 炎症是脑老化和神经变性的特征。作为中枢神经系统的哨兵巨噬细胞， 小胶质细胞在感知和响应CNS环境变化中起重要作用。小胶质细胞监测 CNS用于外来/“非自身”和内源性物质，用于神经保护和神经变性 功能协调发展的在正常生理条件下，小胶质细胞保持相对静止的监视表型; 然而，刺激可使小胶质细胞转化为促炎性M1表型或抗炎性M2表型。 表型小胶质细胞表型转换的控制涉及DNA修饰的调节，主要是 胞嘧啶的甲基化和羟甲基化，其控制基因组可及性和基因表达。 女性中小胶质细胞特异性炎症通路随年龄的过度激活和女性中的性别差异 随着年龄的增长，DNA修饰在大脑老化和神经炎症的性别差异中起着表观遗传作用。 然而，配对的表观基因组学和转录组学研究尚未在海马小胶质细胞中进行， 性别之间的年龄。为了解决这一进展障碍，我们开发了小胶质细胞特异性，他莫昔芬诱导， 转基因NuTRAP模型以允许从谱系追踪的小胶质细胞分离核酸（DNA & RNA）。在 目的1、应用全基因组技术检测海马mC/hmC区小胶质细胞特异性的增龄变化 氧化亚硫酸氢盐测序（WGoxBS）。表观基因组数据，以及来自相同基因组的配对转录组数据， 动物将被用来确定改变的修饰模式在与年龄相关的基因变化中的作用。 表达，基因组调控区差异修饰的富集，并鉴定基因组 用于未来的表观基因组编辑实验。尽管在一些现存的啮齿类动物中， 虽然转基因动物是AD的典型模型，但该领域公认的局限性是转基因动物在100 - 200 ℃时发展AD神经病理学。 年轻时发生，不像散发性AD，后者发生在晚年。新的AD模型，如淀粉样β（Aβ）寡聚体 输注允许在脑老化和性别影响的背景下检查AD相关Aβ神经病理学。在 目的2：我们将联合收割机Aβ-寡聚体输注与我们的新型NuTRAP模型相结合，选择性地分析小胶质细胞特异性 Aβ神经毒性背景下的表观基因组学和转录组学变化。此外，免疫组织化学和 细胞因子/趋化因子面板用于神经胶质增生的读出，以评估衰老对Aβ诱导的小胶质细胞的影响。 两性之间的反应。如果成功的话，这些研究将为性别差异的小胶质细胞 功能与衰老和Aβ相关的神经病理学，并确定性别特异性 治疗干预。未来的研究也将利用这些发现来检查性行为的调节者。 与大脑老化的差异