氟美松对嗜酸粒细胞凋亡的作用及其机制

The effect and mechanism of dexamethasone on apoptosis of blood eosinophil in vitro

目的 探讨氟美松对体外嗜酸粒细胞凋亡的作用及其机制。方法 在不同浓度白细胞介素 (IL) 5和氟美松的条件下体外培养嗜酸粒细胞 ,锥虫蓝拒染法和原位凋亡检测法观察嗜酸粒细胞凋亡的变化及嗜酸粒细胞凋亡抑制基因bcl 2表达的变化。结果 IL 5显著抑制嗜酸粒细胞凋亡 ,氟美松呈浓度和时间依赖性抑制IL 5介导的嗜酸粒细胞存活 ,10 -6mol/L氟美松显著抑制 1× 10 4 U/LIL 5介导的嗜酸粒细胞存活 ,培养 3d嗜酸粒细胞存活率为 (7± 3) % (P <0 .0 1) ,抑制率达 (90± 4) %。IL 5使嗜酸粒细胞bcl 2表达增强 ,氟美松对此具有抑制作用。但高浓度的IL 5 (1× 10 6U/L)可抑制氟美松的凋亡诱导作用。结论 氟美松具有诱导嗜酸粒细胞凋亡的作用 ,其机制可能与抑制嗜酸粒细胞bcl 2表达有关。

Objective To study the effect of glucocorticoid on apoptosis of eosinophil in vitro. Methods Eosinophils were incubated in vitro in the presence of different concentrations of dexamethasone with interleukine 5 (IL 5), with the presence of IL 5 alone as a positive control and medium alone as a negative control. The changes of eosinophil apoptosis were assessed by trypan blue exclusion and in situ tailing techniques and the expression of bcl 2 protein were also observed in the same time. Results IL 5 inhibited the apoptosis of eosinophils in vitro and increased the expression of bcl 2 significantly ( P <0.01). Dexamethasone antagonized IL 5 mediated eosinophil survival in a dose dependent and time dependent manner Dexamethasone at 10 -6 mol/L inhibited significantly eosinophil survival caused by IL 5 (1×10 4 U/L) and decreased the expression of bcl 2 Conclusion Dexamethasone can inhibit IL 5 mediated eosinophil survival and expression of bcl 2, which may be an important mechanism for dexamthasone to induce apoptosis of eosinophil