中性粒细胞胞外陷阱（NETs）通过上调单核细胞PI3K-δ/Akt通路活性增加烟草烟雾暴露诱发的糖皮质激素抵抗?

Neutrophils and mononuclear-macrophages are the most important inflammatory cells in chronic obstructive pulmonary disease (COPD) and play an critical role in airway and pulmonary inflammation. Both of them secrete inflammatory mediators and promote the development of inflammation. However, the interaction of neutrophils with mononuclear-macrophages is remain not clear. Our previous study showed that neutrophils exposed to cigarette smoke (CSE) induced formation of neutrophil extracellular traps (NETs) which amplified the airway and pulmonary inflammation. On the other hand, the exposure of mononuclear cells to CSE increased activity of PI3K-δ /Akt pathway and decreased expression of HDAC2, then causing glucocorticoid resistance. There is a correlation between mononuclear cells and neutrophils in our recent preliminary experiment: NETs induced by CSE could upregulate the activity of PI3K-δ /Akt in mononuclear cells. Therefore we hypothesized that NETs enhances the glucocorticoid resistance of mononuclear cells exposed to CSE by through upregulation activity of PI3K-δ/Akt. The research first observed the effect of NETs produced by neutrophils in COPD patients on PI3K-δ/Akt in mononuclear cells, then try to investigate the effect of NETs on the PI3K-δ/Akt pathway through the in vivo and in vitro study, to determine the target and the effect of corticosteroid resistance.

中性粒细胞及单核-巨噬细胞作为COPD最主要的炎症细胞在肺部炎症中起重要作用，两者均可释放炎症介质促进炎症发展，但其相互作用如何目前尚不清楚。我们既往研究显示:烟草烟雾暴露（CSE）一方面诱导中性粒细胞产生中性粒细胞胞外陷阱（NETs）放大气道炎症，另一方面可上调单核细胞PI3K-δ/Akt/HDAC2路径致糖皮质激素抵抗。近期预实验发现两者存在相关性：CSE刺激中性粒细胞产生的NETs上调单核细胞PI3K-δ/Akt活性，据此提出假说：NETs通过上调单核细胞PI3K-δ/Akt活性增强烟草烟雾暴露诱发的糖皮质激素抵抗。课题首先观察COPD患者中性粒细胞产生的NETs对COPD单核细胞PI3K-δ/Akt的影响，继而通过小鼠COPD模型及细胞体外实验在机制上探讨NETs对CSE刺激单核细胞PI3K-δ/Akt路径作用，以确定作用靶点及对糖皮质激素抵抗影响。

烟草烟雾暴露（CSE）诱导中性粒细胞产生中性粒细胞胞外陷阱（NETs）放大气道炎症，另一方面可上调单核细胞PI3K-δ/Akt/HDAC2路径致糖皮质激素抵抗。NETs对CSE刺激单核细胞PI3K-δ/Akt路径作用，其具体机制尚不清楚。本研究旨在探讨NETs对CSE刺激下单核细胞的糖皮质激素抵抗的作用。NETs刺激的U937细胞进行转录组学检测，所得差异基因行GO、KEGG、GSEA富集分析，提示PI3Kδ/AKT通路是NETs刺激与激素抵抗关系的作用靶点。从非吸烟者、健康吸烟者志愿者和慢性阻塞性肺病受试者中收集外周血单个核细胞、中性粒细胞。U937细胞加入或不加入与红霉素孵育，同时用NETs刺激。测定了PI3K-δ/Akt通路活化情况，以及GR、HDAC2的表达。NETs刺激通过PI3Kδ/AKT通路引起糖皮质激素抵抗，红霉素通过作用于PI3Kδ/AKT减轻NETs引起的糖皮质激素抵抗。本研究阐明了NETs诱发单核细胞的糖皮质激素抵抗的具体机制，同时对红霉素恢复外周血单个核细胞和U937细胞对皮质类固醇的敏感性提供了证据。