Spontaneous apoptosis of neutrophils plays a key role in maintaining immune homeostasis and resolving inflammation. However, the mechanism triggering this apoptosis remains obscure. In the present study, we performed a global metabolomics analysis of neutrophils undergoing spontaneous apoptosis by using hydrophilic interaction chromatography ultra-high-performance liquid chromatography-tandem quadrupole/time-of-flight mass spectrometry and found 23 metabolites and 42 related pathways that were altered in these cells. Among them, glutathione, which is known to be involved in apoptosis, was particularly interesting. We found that L-pyroglutamic acid, glutamate, and their glutathione-mediated embolic pathways were all changed. Our findings confirmed the glutathione levels decreased in apoptotic neutrophils. Exogenous glutathione and LPS treatment delayed neutrophil apoptosis and decreased the levels of pro-apoptotic protein caspase-3. γ-glutamylcyclotransferase, 5-oxoprolinase, and ChaC1, which participated in glutathione degradation, were all activated. At the same time, the down-regulation of ATP production suggested the activity of glutathione biosynthesis may be attenuated even if glutamate-cysteine ligase and glutathione synthase, which are two ATP-dependent enzymes participating in glutathione biosynthesis, were enhanced. To our knowledge, this is the first report highlighting a global metabolomics analysis using hydrophilic interaction chromatography ultra-high-performance liquid chromatography-tandem quadrupole/time-of-flight mass spectrometry and the potential involvement of glutathione depletion in spontaneous apoptosis of neutrophils demonstrating that LPS could delay this process.

中性粒细胞的自发凋亡在维持免疫稳态和解决炎症中起关键作用。然而，触发这种细胞凋亡的机制仍然不清楚。在本研究中，我们使用亲水相互作用色谱超高效液相色谱-串联四极杆/飞行时间质谱对发生自发性凋亡的中性粒细胞进行了全局代谢组学分析，发现 23 种代谢物和 42 种相关途径发生了改变在这些细胞中。其中，已知与细胞凋亡有关的谷胱甘肽尤为有趣。我们发现L-焦谷氨酸、谷氨酸及其谷胱甘肽介导的栓塞途径都发生了变化。我们的研究结果证实了凋亡中性粒细胞的谷胱甘肽水平下降。外源性谷胱甘肽和 LPS 处理延迟了中性粒细胞凋亡并降低了促凋亡蛋白 caspase-3 的水平。参与谷胱甘肽降解的γ-谷氨酰环转移酶、5-氧脯氨酸酶和ChaC1均被激活。同时，ATP产生的下调表明，即使谷胱甘肽-半胱氨酸连接酶和谷胱甘肽合酶这两种参与谷胱甘肽生物合成的ATP依赖性酶得到增强，谷胱甘肽生物合成的活性也可能减弱。据我们所知，