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

项目总结 40%的老年人(65岁)饮酒，而 参与狂欢饮酒的人越来越多。尽管与年龄相关的疾病数量同时增加 神经退行性疾病，如阿尔茨海默病和相关痴呆症，酗酒对 衰老的大脑和神经退行性变还没有得到很好的了解。尽管失控的宿主免疫力和 促炎介质的产生增加是两种年龄的重要和独立的贡献因素- 和酒精相关的神经变性，酒精和高龄对神经炎症的联合作用 不是很好的特征。我们的初步数据显示，在大量接触酒精后， 与年轻小鼠相比，老年小鼠海马区促炎症细胞因子的含量更高。这样做的目的是 建议确定导致酒精引起的神经炎性反应增强的具体机制 大脑老化。激活NLRP3炎症体和小胶质细胞，这两个细胞是中央动脉的驻留巨噬细胞 神经系统，是导致酒精引起的神经炎症和年轻大脑损伤的关键因素。 此外，衰老模型已将NLRP3和小胶质细胞激活增强确立为导致 放大老年大脑中的炎症反应和相关的神经元损伤。具体的 NLRP3在促进包括小胶质细胞在内的乙醇增强神经炎性反应中的作用 激活，在高龄还没有被定义。我们的工作假设是相对于年轻人， 过量酒精暴露导致小胶质细胞激活增强，过度神经炎症和 老年大脑中的相关神经变性。此外，我们假设这些夸大了 老年人对乙醇的反应依赖于NLRP3。为了测试这一点，在目标1中，我们将全面 描述酗酒暴露对神经炎症、神经变性和认知的影响 使用多光谱成像和行为学分析对年轻和老年小鼠的损害。然后，我们将定义 NLRP3在老年和酒精相关的海马区损伤中的作用 利用NLRP3基因敲除的幼年和老年小鼠。在目标2中，我们将阐明NLRP3的细胞特异性作用 取自幼年和老年小鼠的原代小胶质细胞。我们将在体外鉴定小胶质细胞的表型。 乙醇暴露原代小胶质细胞，并采用新的方法使用特异性NLRP3抑制剂OLT1177， 目的：减轻乙醇诱导的原代小胶质细胞炎症反应。加在一起，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 并确定新的治疗靶点，以防止与年龄和酒精相关的神经退化。

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.