IFN-γ促进红系终末分化

摘要

目的 探索IFN-γ对体外红系终末分化的调节作用.方法 用real-time PCR法检测IFN-γR1/R2在血红素(he-min)诱导K562细胞红系分化过程中的表达变化.以IFN-γ处理hemin诱导的K562细胞和人脐血CD34+细胞来源的红系细胞,用real-time PCR检测红系分化标志物CD235a和CD71表达.用联苯胺染色展现IFN-γ处理的K562细胞中血红蛋白含量,通过Westem blot和real-time PCR检测红系相关转录因子GATA1和NFE2的表达.结果 Hemin诱导下分化的K562细胞中IFN-γR1/R2 mRNA先减少后增高,IFN-γ促进K562及造血干祖细胞红系分化晚期CD71及CD235a的表达,增加联苯胺阳性染色率.IFN-γ对红系分化的促进作用具有时间依赖性.机制研究表明IFN-γ可促进红系关键转录因子NFE2的表达.结论 IFN-γ促进K562细胞及人脐血造血干祖细胞的红系终末分化.%Objective To study the effects of interferon γ(IFN-γ) on terminal erythroid differentiation.Methods RT-qPCR was used to detect the expression of IFN-γ receptors during erythroid differentiation of K562 induced by hemin.Both hemin-induced K562 cells and human umbilical cord CD34+ cell derived primary erythroid cells were treated with IFN-γ.Erythroid differentiation of the cells was evaluated using RT-qPCR to detect the mRNA level of erythroid specific surface markers CD71 and CD235a,and benzidine staining assay was applied to explore the change of hemoglobin expression.Results The expression of IFN-γ receptors in K562 cells decreased and climbed up again after reaching the lowest point at 48 h of hemin induction.IFN-γ treatment increased CD71 and CD235a expression in both hemin-induced K562 cells and the later stage (E15D) primary erythroid cells.Benzidine staining showing increased globin protein expression in hemin-induced K562 cells after IFN-γstimulation.Furthermore,our results indicated that IFN-γ promoted hemin-induced K562 erythroid differentiation in a time dependent manner.Mechanistically,the results showed that IFN-γ treatment stimulated the expression of erythroid transcription factors NFE2,which was critically for erythroid maturation.Conclusions IFN-γaccelerates terminal erythroid differentiation in hemin-induced K562 cells and human umbilical cord CD34+ derived primary erythroid cells.