白细胞介素6与血小板活化因子对中性粒细胞凋亡的抑制作用

Role of interleukin-6 and platelet-activating factor in delaying neutrophil apoptosis

应用血浆 Percoll梯度分离技术分离健康供血者的中性粒细胞 (PMN)并以 2× 10 7PMN/ml培养2 4h,实验分白细胞介素 6 (IL- 6 )、血小板活化因子 (PAF)单独处理组。 PAF受体拮抗剂 BN5 2 0 2 1预处理后再以 PAF、IL - 6分别处理组。吖啶橙和溴乙啶染色 ,荧光显微镜下观察细胞形态并记数进行细胞凋亡的定性定量分析。结果表明 ,IL- 6和 PAF均有抑制 PMN凋亡的作用。PAF受体拮抗剂 BN5 2 0 2 1能消除 IL- 6和PAF抑制 PMN凋亡的作用。提示 IL - 6抑制 PMN凋亡的机制可能是通过 PAF而实现的。从而从一个侧面说明了 IL- 6和 PAF介导的损伤后炎症反应及继发性器官功能衰竭可能与抑制中性粒细胞凋亡加剧炎症反应有关。

In the present study we investigated the role of platelet activating factor (PAF) and interleukin 6 (IL 6) in delaying polymorphonuclear neutrophil (PMN) apoptosis. Isolation of PMN was performed by using the discontinuous plasma Percoll gradient technique. PMN was cultured in enriched RPMI 1640 media at 2×10 7 PMN/ml for 24h. Subgroups were treated with IL 6 or PAF or pretreated with PAF receptor antagonist BN52021 before IL 6 or PAF were added. Morphological assessment and quantitation of apoptosis were performed with acrodine/ethidium bromide stain and epifluorescent microscope. The results showed that both IL 6 and PAF suppressed PMN apoptosis. Pretreatment of PMN with BN52021 abrogated the effects of IL 6 and PAF. It is suggested that PAF may be a crucial cytokine in the suppression of PMN apoptosis. These observations may contribute to elucidating the mechanisms of IL 6 and PAF in mediating postinjury hyperinflammation and secondary organ dysfunction and provide a clue for the prevention and treatment of the conditions.