Omega-3 Fatty Acid Suppression of Silica-induced Inflammasome Activation in a Novel Alveolar Macrophage Model

摘要 在自身免疫性疾病和炎性疾病的发展中，免疫球蛋白组起着关键作用。在这个亲- 因此，我将讨论饮食中ω-3脂肪酸二十二碳六烯酸（DHA）在预防 由可吸入有毒物质结晶二氧化硅（cSiO2）引起的炎症。此前，我们的实验室发现， 补充DHA剂量依赖性地降低了cSiO2触发的自体免疫的几个特征的水平， 狼疮易感小鼠模型中的免疫力。在该模型中，全身性炎症发展的关键事件是 cSiO2诱导的肺泡巨噬细胞（AMph）毒性，涉及NLRP 3炎症因子的激活， masome和释放有效的IL-1细胞因子。目前的文献和我的初步实验表明 DHA及其代谢物，称为专门的促分解介质（SPM），可能会减弱这种再分解。 sponse。NLRP 3炎性体的激活，与许多炎症和自身免疫性疾病有关 条件下，需要初始引发步骤，在此期间，NF-κ B家族转录因子上调炎症因子。 masome组分和pro-IL-1细胞因子。抗炎性G蛋白偶联受体（GPCR）具有 已被鉴定为结合DHA或SPM并抑制NF-κ B活化。然而，在体外阐明的分子， AMph中DHA保护的事件受到可从单个小鼠获得的细胞数量低（~105）的限制。 为了解决这个问题，我使用了马克斯普朗克研究所（MPI）细胞。MPI细胞是自我更新的巨噬细胞系 通过在补充GM-CSF的培养基中培养胎鼠肝脏获得，并且表型类似于 嗯。我的初步数据表明，IL-1细胞因子释放响应LPS引发和cSiO2治疗， 通过补充DHA来减少。我建议补充DHA可以增加细胞膜中的DHA MPI细胞，它可以被释放和代谢为SPM。游离DHA及其SPM可以激活抗炎症， 以自分泌或旁分泌方式抑制炎症性GPCR以减弱NF-κ B信号传导，我假设这是一种原发性炎症性GPCR。 它们通过玛丽机制防止cSiO2诱导的炎症。在目标1中，磷脂结合- 将测量DHA的比例，然后将测量DHA对IL-1细胞因子释放和NF-kB活化的影响。 评估。我还将用化学激动剂、拮抗剂和特异性GPCR的siRNA处理细胞，以验证它们的功能。 DHA信号的作用。在目标2中，将测量补充有DHA的细胞的脂质代谢物谱。我 然后将确定SPM抑制NF-κ B活化和IL-1细胞因子释放的程度。最后，化学- 药理学拮抗剂和siRNA将用于研究所提出的SPM受体的参与。这些前- 实验将在具有必要资源的支持性环境中进行， 形容词我的全面培训计划提供个人和专业发展，这将有助于我 成为一名成功的独立研究者。

ABSTRACT The exposome plays a critical role in the development of autoimmune and inflammatory diseases. In this pro- posal, I will address the role of the dietary ω-3 fatty acid docosahexaenoic acid (DHA) in protecting against inflammation induced by the respirable toxicant crystalline silica (cSiO2). Previously, our laboratory found that supplementation with DHA dose-dependently decreased levels of several features of cSiO2-triggered autoim- munity in a lupus-prone mouse model. A key event in the development of systemic inflammation in this model is cSiO2-induced toxicity of the alveolar macrophage (AMph), which involves activation of the NLRP3 inflam- masome and release of potent IL-1 cytokines. The current literature and my preliminary experiments suggest that DHA and its metabolites, known as specialized proresolving mediators (SPMs), may attenuate this re- sponse. Activation of the NLRP3 inflammasome, which is implicated in many inflammatory and autoimmune conditions, requires an initial priming step, during which NF-kB family transcription factors upregulate inflam- masome components and pro-IL-1 cytokines. Anti-inflammatory G-protein coupled receptors (GPCRs) have been identified that bind DHA or SPMs and inhibit NF-kB activation. However, in vitro elucidation of the molecular events of DHA protection in AMph is limited by the low number of cells attainable from a single mouse (~105). To address this, I used Max Planck Institute (MPI) cells. MPI cells are a self-renewing macrophage cell line derived by culturing fetal mouse livers in GM-CSF-supplemented medium and are phenotypically similar to AMph. My preliminary data show that IL-1 cytokine release in response to LPS-priming and cSiO2 treatment is attenuated by DHA supplementation. I propose that DHA supplementation increases DHA in the cell membrane of MPI cells, which can be released and metabolized to SPMs. Free DHA and its SPMs can activate anti-inflam- matory GPCRs in an autocrine or paracrine manner to attenuate NF-kB signaling, which I hypothesize is a pri- mary mechanism by which they protect against cSiO2-induced inflammation. In Aim 1, the phospholipid incorpo- ration of DHA will be measured, and then effects of DHA on IL-1 cytokine release and NF-kB activation will be assessed. I will also treat cells with chemical agonists, antagonists, and siRNA for specific GPCRs to verify their role in DHA signaling. In Aim 2, the lipid metabolite profile of cells supplemented with DHA will be measured. I will then determine the extent to which SPMs suppress NF-kB activation and IL-1 cytokine release. Lastly, chem- ical antagonists and siRNA will be used to investigate the involvement of proposed SPM receptors. These ex- periments will be performed in a supportive environment with the necessary resources to accomplish these ob- jectives. My comprehensive training plan provides personal and professional development, which will assist me in becoming a successful independent researcher.