Department of Anesthesiology, Columbia University, 622 W. 168th St., P&S Box 46, New York, NY, 10032, USA.
Department of Surgery, Morristown Medical Center, Morristown, NJ, USA.
Purinergic Signal. 2022 Sep;18(3):345-358. doi: 10.1007/s11302-022-09884-0. Epub 2022 Jul 15.
Extracellular adenosine is a biologically active signaling molecule that accumulates at sites of metabolic stress in sepsis. Extracellular adenosine has potent immunosuppressive effects by binding to and activating G protein-coupled A adenosine receptors (AARs) on the surface of neutrophils. AAR signaling reproduces many of the phenotypic changes in neutrophils that are characteristic of sepsis, including decreased degranulation, impaired chemotaxis, and diminished ability to ingest and kill bacteria. We hypothesized that AARs also suppress neutrophil aging, which precedes cell death, and N1 to N2 polarization. Using human neutrophils isolated from healthy subjects, we demonstrate that AAR stimulation slows neutrophil aging, suppresses cell death, and promotes the polarization of neutrophils from an N1 to N2 phenotype. Using genetic knockout and pharmacological blockade, we confirmed that AARs decrease neutrophil aging in murine sepsis induced by cecal ligation and puncture. AARs expression is increased in neutrophils from septic patients compared to healthy subject but AAR expression fails to correlate with aging or N1/N2 polarization. Our data reveals that AARs regulate neutrophil aging in healthy but not septic neutrophils.
细胞外腺苷是一种生物活性信号分子,在败血症的代谢应激部位积累。细胞外腺苷通过与中性粒细胞表面的 G 蛋白偶联 A 腺苷受体 (AAR) 结合并激活它们,具有强大的免疫抑制作用。AAR 信号转导再现了中性粒细胞中许多与败血症相关的表型变化,包括脱颗粒减少、趋化作用受损以及吞噬和杀死细菌的能力降低。我们假设 AAR 还可以抑制中性粒细胞衰老,即细胞死亡之前的衰老,以及 N1 到 N2 的极化。使用从健康受试者中分离的人中性粒细胞,我们证明 AAR 刺激可减缓中性粒细胞衰老,抑制细胞死亡,并促进从 N1 到 N2 表型的中性粒细胞极化。通过基因敲除和药物阻断,我们证实 AAR 在盲肠结扎和穿刺诱导的小鼠败血症中减少中性粒细胞衰老。与健康受试者相比,败血症患者的中性粒细胞中 AAR 的表达增加,但 AAR 的表达与衰老或 N1/N2 极化无关。我们的数据表明,AAR 调节健康中性粒细胞中的中性粒细胞衰老,但不调节败血症中性粒细胞中的中性粒细胞衰老。