The Neuroinflammatory Impact of Binge Ethanol Exposure in Aged Mice: A Role for NLRP3.

项目摘要 40%的老年人（>65岁）饮酒， 参与酗酒的人越来越多尽管与年龄有关的死亡人数同时增加， 神经退行性疾病，如阿尔茨海默病和相关痴呆症，酗酒对 大脑老化和神经退行性变还没有得到很好的理解。尽管宿主免疫功能失调， 促炎介质的产生增加是年龄- 酒精和高龄对神经炎症的综合作用 并没有很好地描述。我们的初步数据表明，在酒精暴露后， 促炎细胞因子在海马体中的含量在老年小鼠中比年轻小鼠高。这个目标 一项建议是确定导致乙醇引起的神经炎症反应增强的具体机制， 大脑老化NLRP 3炎性小体和小胶质细胞（中央巨噬细胞）的激活 神经系统，是导致酒精诱导的神经炎症和损伤的年轻大脑的关键因素。 此外，衰老模型已经建立了NLRP 3和增强的小胶质细胞活化作为导致衰老的核心因素。 炎症反应的增强和老年大脑中相关的神经元损伤。具体 NLRP 3在驱动对乙醇的增强的神经炎症反应中的作用，包括小胶质细胞 激活，在先进的年龄尚未被定义。我们的工作假设是，相对于年轻人， 酗酒暴露会导致小胶质细胞的活化增强，过度的神经炎症， 相关的神经退化。此外，我们假设这些夸大的 老年人对乙醇的反应依赖于NLRP 3。为了验证这一点，在目标1中，我们将全面 描述酗酒暴露对神经炎症、神经变性和认知功能的影响。 使用多光谱成像和行为测定对年轻和老年小鼠的损伤进行了研究。然后我们将定义 NLRP 3作为高龄和乙醇相关海马损伤的重要贡献者的作用 利用NLRP 3敲除的年轻和老年小鼠。在目标2中，我们将阐明NLRP 3的细胞特异性作用， 在从年轻和老年小鼠收集的初级小胶质细胞中。我们将在离体后表征小胶质细胞表型， 原代小胶质细胞的乙醇暴露，并采取新的方法使用特异性NLRP 3抑制剂，OLT 1177， 以减轻年轻和老年大脑中初级小胶质细胞中乙醇诱导的炎症。所有这些 研究将揭示衰老过程中酒精滥用如何导致神经退行性疾病的发病机制 并确定新的治疗目标，以防止年龄和酒精相关的神经退行性病变。

PROJECT SUMMARY Forty percent of aged adults (>65 years of age) consume alcohol and the population of aged adults that participate in binge drinking is growing. Despite a concurrent increase in the number of age-related neurodegenerative diseases like Alzheimer's disease and related dementias, the effect binge drinking has on the aged brain and neurodegeneration is not well understood. Although dysregulated host immunity and heightened production of pro-inflammatory mediators are significant and independent contributors to both age- and alcohol-related neurodegeneration, the combined effect of alcohol and advanced age on neuroinflammation is not well characterized. Our preliminary data demonstrate that following binge ethanol exposure, the production of pro-inflammatory cytokines in the hippocampus is greater in aged mice compared to young. The goal of this proposal is to identify specific mechanisms leading to heightened neuroinflammatory responses to ethanol in the aged brain. Activation of both the NLRP3 inflammasome and microglia, the resident macrophages of the central nervous system, are critical factors leading to alcohol-induced neuroinflammation and injury in the young brain. Moreover, aging models have established NLRP3 and heightened microglia activation as central factors leading to amplified inflammatory responses and associated neuronal damage in the aged brain. The specific contribution of NLRP3 in driving enhanced neuroinflammatory responses to ethanol, including microglia activation, in advanced age has not yet been defined. It is our working hypothesis that relative to young, binge ethanol exposure leads to heightened activation of microglia, excessive neuroinflammation and associated neurodegeneration in the aged brain. Moreover, we hypothesize that these exaggerated responses to ethanol in advanced age are NLRP3 dependent. To test this, in Aim 1 we will comprehensively characterize the effect of binge ethanol exposure on neuroinflammation, neurodegeneration, and cognitive impairment in young and aged mice using multispectral imaging and behavioral assays. We will then define the role of NLRP3 as an important contributor for advanced age- and ethanol-related hippocampal damage by making use of NLRP3 knockout young and aged mice. In Aim 2, we will elucidate the cell-specific role of NLRP3 in primary microglia harvested from young and aged mice. We will characterize microglia phenotype after ex vivo ethanol exposure of primary microglia and take the novel approach to use the specific NLRP3 inhibitor, OLT1177, to alleviate ethanol-induced inflammation in primary microglia from the young and aged brain. Together, these studies will unveil how alcohol-misuse during aging may contribute to neurodegenerative disease pathogenesis and identify new therapeutic targets to prevent age- and alcohol-related neurodegeneration.