Rheumatoid arthritis (RA) is an inflammatory autoimmune disease mediated by immune cell dysfunction for which there is no universally effective prevention and treatment strategy. As primary effector cells, neutrophils are important in the inflammatory joint attack during the development of RA. Here, we used single-cell sequencing technology to thoroughly analyze the phenotypic characteristics of bone marrow-derived neutrophils in type II collagen (COL2)-induced arthritis (CIA) models, including mice primed and boosted with COL2. We identified a subpopulation of neutrophils with high expression of neutrophil cytoplasmic factor 1 (NCF1) in primed mice, accompanied by a characteristic reactive oxygen species (ROS) response, and a decrease in Ncf1 expression in boosted mice with the onset of arthritis. Furthermore, we found that after ROS reduction, arthritis occurred in primed mice but was attenuated in boosted mice. This bidirectional effect of ROS suggested a protective role of ROS during immune priming. Mechanistically, we combined functional assays and metabolomics identifying Ncf1-deficient neutrophils with enhanced migration, chemotactic receptor CXCR2 expression, inflammatory cytokine secretion, and Th1/Th17 differentiation. This alteration was mainly due to the metabolic reprogramming of Ncf1-deficient neutrophils from an energy supply pathway dominated by gluconeogenesis to an inflammatory immune pathway associated with the metabolism of histidine, glycine, serine, and threonine signaling, which in turn induced arthritis. In conclusion, we have systematically identified the functional and inflammatory phenotypic characteristics of neutrophils under ROS regulation, which provides a theoretical basis for understanding the pathogenesis of RA, to further improve prevention strategies and identify novel therapeutic targets.

中文翻译：

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活性氧产生量低的中性粒细胞在免疫启动过程中被激活并促进关节炎的发展


类风湿性关节炎 （RA） 是一种由免疫细胞功能障碍介导的炎症性自身免疫性疾病，目前尚无普遍有效的预防和治疗策略。作为主要的效应细胞，中性粒细胞在 RA 发展过程中的炎症性关节攻击中很重要。在这里，我们使用单细胞测序技术彻底分析了 II 型胶原蛋白 （COL2） 诱导的关节炎 （CIA） 模型中骨髓来源的中性粒细胞的表型特征，包括用 COL2 引发和增强的小鼠。我们在启动小鼠中鉴定了一个中性粒细胞细胞胞质因子 1 （NCF1） 高表达的中性粒细胞亚群，伴有特征性活性氧 （ROS） 反应，并且在关节炎发作时增强小鼠中 Ncf1 表达降低。此外，我们发现 ROS 降低后，关节炎发生在初发小鼠中，但在增强小鼠中减弱。ROS 的这种双向效应表明 ROS 在免疫启动过程中具有保护作用。从机制上讲，我们结合了功能测定和代谢组学鉴定 Ncf1 缺陷的中性粒细胞，这些中性粒细胞迁移、趋化受体 CXCR2 表达、炎性细胞因子分泌和 Th1/Th17 分化增强。这种改变主要是由于 Ncf1 缺陷型中性粒细胞的代谢重编程，从以糖异生为主的能量供应途径转变为与组氨酸、甘氨酸、丝氨酸和苏氨酸信号代谢相关的炎症免疫途径，进而诱导关节炎。 综上所述，我们系统地鉴定了 ROS 调控下中性粒细胞的功能和炎症表型特征，为理解 RA 的发病机制提供了理论基础，为进一步改进预防策略和确定新的治疗靶点提供了理论依据。