NF-kappaB and Mitochondrial Signals as Positive and Negative Regulators of Inflammation

摘要 这是对行政副刊的要求，以扩大我们目前对NLRP3监管的研究 炎症体激活，在父母奖AI043477下进行，目的是开发一种新型的抗炎药 新冠肺炎相关性急性呼吸窘迫综合征的炎症治疗。像它的前身一样， 严重急性呼吸综合征相关冠状病毒--新型SARS-CoV-2 新冠肺炎大流行的起因是病毒，它可以引起下呼吸道感染，从而导致病毒性肺炎 这可能会发展为急性呼吸窘迫综合征。ARDS是一种潜在的致命的严重疾病，据估计 在新冠肺炎大流行之前，每年在美国造成20万例病例，现在更多。几个先天的 包括血小板、中性粒细胞、巨噬细胞和树突状细胞在内的免疫细胞类型参与了安装 ARDS中失控的炎症和组织损伤，无论其最初的触发因素如何。这些细胞产生 许多炎症介质和细胞因子对最初的侮辱做出反应，在新冠肺炎的情况下 是肺上皮细胞内的病毒复制和随后的细胞死亡。垂死的上皮细胞释放损伤 相关分子模式(DAMP)，其中白介素1α和三磷酸腺苷是首要的。把这些放在一起 分子导致肺泡巨噬细胞的启动(IL-1a)和NLRP3炎症小体的激活(ATP)， 它介导成熟的IL-1β和IL-18的产生，从而放大和传播炎症反应 这最终导致了ARDS。抑制这种反应应该会大大降低相关的死亡率和发病率。 还有新冠肺炎。然而，由于用现有药物完全阻断IL-1会增加细菌感染的风险 感染，唯一适合抑制SARS-CoV-2诱导的急性呼吸窘迫综合征的策略是选择性IL-1α 阻断或抑制与抗微生物防御无关的NLRP3炎症体。到目前为止, 靶向下游细胞因子IL-6的结果好坏参半，IL-1a特异性抗体仍然存在 正在进行临床开发。此外，抗细胞因子药物相当昂贵。我们最近发现了广泛的 处方抗糖尿病药物二甲双胍是NLRP3炎症小体激活和IL-1β的有效抑制剂 激活的巨噬细胞在体外和体内产生。因此，我们现在要求额外的资金来进行测试 并提高二甲双胍阻止ARDS发作的能力，首先是在内毒素攻击的BL6小鼠，然后是在 SARS-CoV-2感染hACE2转基因小鼠。因为二甲双胍的半衰期很短，而巨噬细胞则不是 表达肝细胞表达的二甲双胍转运体，我们将检测是否负载了二甲双胍 通过吸入给药的纳米颗粒或外切体可以更有效地抑制SARS-CoV-2引发的ARDS。 重要的是，二甲双胍是一种非常安全和廉价的药物，具有很强的抗衰老性能，可能是 进一步的价值，在减轻有充分记录的ARDS和新冠肺炎风险的年龄相关增加，归因于 到炎症老化。

ABSTRACT This is a request for an Administrative Supplement to expand our current research on the regulation of NLRP3 inflammasome activation, carried out under parent award AI043477, with the goal of developing a novel anti- inflammatory therapy for COVID-19 related acute respiratory distress syndrome (ARDS). Like its predecessor, the Severe Acute Respiratory Syndrome-related coronavirus (SARS-CoV-1), the novel SARS-CoV-2 virus, the cause of the COVID-19 pandemic, can establish lower airway infections that cause viral pneumonia that may progress to ARDS. ARDS is a potentially fatal, severe medical condition that has been estimated to cause 200,000 yearly cases in the U.S., prior to the COVID-19 pandemic and many more now. Several innate immune cell types including platelets, neutrophils, macrophages and dendritic cells partake in mounting uncontrolled inflammation and tissue injury in ARDS, regardless of its initial trigger. These cells produce numerous inflammatory mediators and cytokines in response to the initial insult, which in the case of COVID-19 is viral replication within lung epithelial cells and subsequent cell death. Dying epithelial cells release damage associated molecular patterns (DAMPs), of which IL-1α and ATP are of primary importance. Together these molecules lead to priming (IL-1a) of alveolar macrophages and activation (ATP) of the NLRP3 inflammasome, which mediates production of mature IL-1β and IL-18, which amplify and propagate the inflammatory response that culminates in ARDS. Inhibition of this response should reduce much of the mortality and morbidity associated with COVID-19. However, since total IL-1 blockade with currently available drugs increases the risk of bacterial infections, the only suitable strategies for inhibition of SARS-CoV-2 elicited ARDS are either selective IL-1α blockade or inhibition of the NLRP3 inflammasome, which is not involved in anti-microbial defenses. So far, targeting of the downstream cytokine IL-6 had produced mixed results and IL-1a specific antibodies are still under clinical development. Moreover, anti-cytokine drugs are quite costly. We recently found the widely prescribed anti-diabetic drug metformin to be an effective inhibitor of NLRP3 inflammasome activation and IL-1β production by activated macrophages in vitro and in vivo. Accordingly, we now ask for additional funding to test and improve the ability of metformin to block the onset of ARDS, first in LPS-challenged Bl6 mice and then in SARS-CoV-2 infected hACE2-transgenic mice. As metformin has a short half-life and macrophages do not express the metformin transporters expressed by hepatocytes, we will examine whether metformin-loaded nanoparticles or exosomes given by inhalation allow for more effective inhibition of SARS-CoV-2 elicited ARDS. Importantly, metformin is a very safe and inexpensive drug with strong anti-aging properties that may be of further value in attenuating the well documented age-related increases in ARDS and COVID-19 risk, attributed to inflamma-aging.