Blockade of macrophage-associated programmed death 1 inhibits the pyroptosis signalling pathway in sepsis
Blockade of macrophage-associated programmed death 1 inhibits the pyroptosis signalling pathway in sepsis
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DOI：
10.1007/s00011-021-01493-8
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发表时间：
2021-08-11
影响因子：
6.7
通讯作者：
Ying, Binwu
中科院分区：
文献类型：
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作者：
Fu, Yang;Wang, Denian;Ying, Binwu
目的程序性死亡蛋白1（PD-1）和巨噬细胞是脓毒症引起的炎症性疾病中最有意义的候选者。我们的目的是研究单核细胞PD-1和脓毒症严重程度之间的关系，以及阻断巨噬细胞相关PD-1导致脓毒症炎症性疾病的机制。材料与方法我们首先在一项观察性研究中测量了单核细胞亚群上PD-1的表达是否与脓毒症的严重程度临床相关。本研究包括42名脓毒症患者和16名健康对照（HC），其血清炎症因子通过Luminex MagPix检测。然后，我们通过RNA测序研究了PD-1阻断对通过盲肠结扎穿孔（CLP）构建的脓毒症小鼠（C57 BL/6小鼠）巨噬细胞的影响。通过Western blot在LPS刺激的RAW 264. 7细胞中验证通过RNA-seq筛选的阳性基因。结果脓毒症和脓毒症休克患者外周血CD 14（+）CD 16（+）单核细胞（中间型单核细胞，IM Mo）PD-1的表达明显高于HC。对脓毒症患者血清细胞因子的进一步分析显示，IL-6和TNF-α的水平显著高于HC，而脓毒症患者血清PD-1水平降低。更有趣的是，阻断PD-1对脓毒症小鼠巨噬细胞的作用抑制了NLRP 3/Caspase-4/AKT 2/STAT 3的基因表达水平。在用PD-1抗体处理的LPS刺激的RAW 264. 7细胞中，与焦亡相关的蛋白质水平（包括NLRP 3、Caspase 4、GSDMD和NT-GSDMD）显著降低。结论PD-1高表达的中间型单核细胞可能参与了脓毒症的发生发展。PD-1可能在脓毒症中调节细胞凋亡信号通路中起关键作用。
Objective Programmed death 1 (PD-1) and macrophages are the most intriguing candidates in sepsis-induced inflammatory disorders. We aimed to investigate the association between monocyte PD-1 and sepsis severity and the mechanism by which blocking macrophage-associated PD-1 causes inflammatory disorders in sepsis. Materials and methods We first measured whether the expression of PD-1 on the monocyte subset is clinically associated with sepsis severity in an observational study. This study included 42 septic patients and 16 healthy controls (HCs) whose serum inflammatory factors were examined by Luminex MagPix. Then, we investigated the effect of PD-1 blockade on macrophages from septic mice (C57BL/6 mice) constructed by caecal ligation and puncture (CLP) via RNA sequencing. The positive genes screened by RNA-seq were verified in LPS-stimulated RAW264.7 cells by Western blot. Results The results showed that the expression of PD-1 on CD14(+)CD16(+) monocytes (intermediate monocytes, IM Mo) was significantly higher in both septic and septic shock patients than in HCs. Further analysis of serum cytokines in septic patients showed that the levels of IL-6 and TNF-alpha were significantly higher than those in HCs, while serum PD-1 levels were decreased in septic patients. More interestingly, blockade of PD-1 on macrophages from septic mice suppressed the gene expression levels of NLRP3/Caspase-4/AKT2/STAT3. The protein levels associated with pyroptosis including NLRP3, Caspase4, GSDMD and NT-GSDMD were significantly decreased in LPS-stimulated RAW264.7 cells treated with PD-1 antibody. Conclusion Our results suggested that intermediate monocytes with high expression of PD-1 may be involved in the progression of sepsis. PD-1 might play a critical role in regulating the pyroptosis signalling pathway in sepsis.