Impact of Heightened ER Stress on NLRP3 Activation in Aged Lung during Infection

感染期间内质网应激升高对老化肺 NLRP3 激活的影响

• 批准号: 10207384
• 负责人: Heather Winona Stout Delgado
• 金额: $ 42.38万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10207384
• 关键词: ATF6 gene; Adult; Age; Aging; Animal Model; Bacterial Antibiotic Resistance; Biological Models; CASP1 gene; Cell Culture Techniques; Cells; Clinical; Complex; Cytoprotection; Data; Defect; Disease; Edema; Elderly; Endoplasmic Reticulum; GPRC6A gene; Gene Expression; Genetic Transcription; Homeostasis; Human; IL18 gene; ITPR1 gene; Immune response; Impairment; In Vitro; Infection; Inflammasome; Innate Immune Response; Interleukin-1 beta; Knowledge; Link; Lung; Lung infections; Maintenance; Mediating; Mediator of activation protein; Mitochondria; Molecular; Morbidity - disease rate; Organelles; Outcome; Pathogenesis; Pathogenicity; Pathway interactions; Pneumococcal Infections; Population; Process; Production; Protein Biosynthesis; Proteins; Regulation; Regulatory Pathway; Research Proposals; Role; STIM1 gene; Signal Pathway; Signal Transduction; Stimulus; Streptococcus pneumoniae; Stress; Techniques; Testing; Therapeutic; Therapeutic Intervention; Time; Translations; Vaccination; adaptive immune response; aged; aging population; design; endoplasmic reticulum stress; improved; in vivo; infection rate; innovation; mitochondrial dysfunction; mortality; mouse model; novel therapeutics; programs; protein expression; protein function; response; sensor; therapeutic evaluation; tissue injury; treatment strategy

Project Summary With an aging population and pulmonary infections becoming an increasingly significant cause of morbidity and mortality, there is an urgent need to investigate molecular pathways underlying these impairments and devise new therapeutics that can stimulate innate immune responses within this population. Our results demonstrate aged hosts have impaired inflammasome activation, decreased gene expression of several key components of the NLRP3 signaling pathway, reduced caspase-1 activity, and diminished IL1β production in response to in vitro and in vivo infection with S. pneumoniae. Using in vitro and in vivo aging murine models of S. pneumoniae infection, we will employ cellular and molecular techniques to test our overall hypothesis that the NLRP3 inflammasome is necessary for protection against S. pneumoniae and age associated decreases in ER and mitochondrial Ca2+ homeostasis results in impaired activation of the NLRP3 inflammasome in aged lung; thereby, resulting in increased bacterial pathogenesis, tissue injury, and pneumonic edema in the elderly lung. To test this hypothesis, we will examine the impact of heightened ER stress and the unfolded protein response (UPR) on inflammasome activity (Aim 1) and the impact of aging on the maintenance of ER Ca2+ homeostasis and subsequent modulation of inflammasome activity (Aim 2) in aged lung during S. pneumoniae infection. Summary and impact: As pulmonary pneumococcal infections remain a substantial cause of morbidity and mortality in the elderly, even in an era of routine adult vaccination, there is a pressing need to identify mechanistic pathways that regulate innate immune responses and investigate novel therapeutics and treatment strategies that reduce serious disease and improve clinical outcomes. Despite the identification of factors that modulate the inflammasome, the impact of aging and age-enhanced levels of ER stress on the regulation of NLRP3 responses, specifically in response to pathogenic stimuli, has not been extensively studied. By establishing and dissecting a pivotal mechanistic link between ER stress regulation and inflammasome signaling in aged lung during S. pneumoniae infection, this research proposal has high potential to elucidate innovative regulatory pathways, expand current understanding of age associated changes in ER homeostasis. Therapeutic strategies designed to target defects in innate signaling in the aged host will aid in circumventing emergent strains of antibiotic resistant bacteria that continue to develop and may be utilized for treatment against a wide variety of pathogenic stimuli. Completion of the aims proposed in this R01 will further define the role of the NLRP3 inflammasome as an important innate signaling pathway during S. pneumoniae infections as well as yield new therapeutics that can be readily tested in primary human cells and evaluated in additional model systems.

项目概要 随着人口老龄化和肺部感染成为发病率和发病率日益重要的原因 死亡率，迫切需要研究这些损伤背后的分子途径并设计 可以刺激该人群先天免疫反应的新疗法。我们的结果表明 老年宿主的炎症小体激活受损，几个关键成分的基因表达降低 NLRP3 信号通路，降低 caspase-1 活性，并减少 IL1β 的产生，以响应 肺炎链球菌的体外和体内感染。使用肺炎链球菌的体外和体内衰老小鼠模型 感染，我们将采用细胞和分子技术来检验我们的总体假设，即 NLRP3 炎症小体对于预防肺炎链球菌以及年龄相关的 ER 和 ER 下降是必要的。 线粒体 Ca2+ 稳态导致衰老肺中 NLRP3 炎症小体的激活受损； 从而导致老年人肺部细菌发病、组织损伤和肺水肿增加。 为了检验这一假设，我们将检查内质网应激升高和未折叠蛋白质反应的影响 (UPR) 对炎症小体活动（目标 1）的影响以及衰老对维持 ER Ca2+ 稳态的影响 以及随后在肺炎链球菌感染期间调节老化肺部的炎症小体活动（目标 2）。 摘要和影响：由于肺肺炎球菌感染仍然是发病率和死亡率的一个重要原因， 即使在成人常规接种疫苗的时代，也迫切需要确定老年人的死亡率 调节先天免疫反应并研究新疗法的机制途径 减少严重疾病并改善临床结果的治疗策略。尽管鉴定出 调节炎症小体的因素、衰老和随年龄增加的内质网应激水平的影响 NLRP3 反应的调节，特别是对致病刺激的反应，尚未得到广泛的研究 研究过。通过建立和剖析 ER 应激调节与 肺炎链球菌感染期间老化肺部的炎症小体信号转导，这项研究提案具有很高的潜力 阐明创新的监管途径，扩大目前对 ER 年龄相关变化的理解 体内平衡。针对老年宿主先天信号缺陷的治疗策略将有助于 规避不断发展并可用于抗生素耐药性细菌的新菌株 针对多种致病刺激的治疗。完成本 R01 中提出的目标将进一步 定义 NLRP3 炎症小体作为肺炎链球菌感染过程中重要的先天信号通路的作用 感染以及产生新的疗法，可以很容易地在原代人类细胞中进行测试并在 额外的模型系统。