促红细胞生成素预防人脐静脉内皮细胞凋亡的作用

目的 建立氧化低密度脂蛋白(ox-LDL)诱导培养人脐静脉内皮细胞(HUVECs)凋亡模型,探讨促红细胞生成素(EPO)对ox-LDL诱导HUVECs凋亡的影响.方法 取体外培养3～6代的HUVECs用于实验.实验分为两组:一组细胞予以不同浓度(6.25、50、100 kU/L)重组人促红细胞生成素(rhEPO)预处理24 h,再加入100 mg/L ox-LDL孵育48 h;另一组细胞加入反式或顺式LOX-1 mRNA预处理24 h,再加入 100 mg/L 的ox-LDL孵育12 h.采用存活率、凋亡率和Bcl-2/Bax比值评价细胞凋亡情况.结果 与ox-LDL组比较,随rhEPO浓度的递增,细胞存活率增高,细胞凋亡率降低,凋亡蛋白Bcl-2/Bax比值增高(P均<0.05),呈剂量依赖性.反式LOX-1 mRNA(0.5 μmol/L)预处理组凋亡蛋白Bcl-2/Bax比值较ox-LDL组明显增高(P<0.05);顺式LOX-1 mRNA(0.5 μmol/L)预处理组Bcl-2/Bax比值与ox-LDL组则无明显差异.结论 ox-LDL可以诱导HUVECs凋亡,并且通过LOX-1 mRNA来调节,rhEPO可增高Bcl-2/Bax比值,抑制ox-LDL诱导的HUVECs凋亡.

Mechanism of inhibition of apoptosis of human umbilical vein endothelial cells induced by oxidized-low density lipoprotein by erythropoietin

Objective To explore the protective effect of erythropoietin (EPO) against oxidized-low density lipoprotein (ox-LDL)-induced apoptosis in human umbilical vein endothelial cells (HUVECs) in an ox-LDL induced apoptosis model. Methods Thirdsixth passage of cultured HUVECs were used,and they were divided into two groups. The cells were pretreated with different concentrations (6.25,50,100 kU/L) of recombinant human erythropoietin (rhEPO) for 24 hours,then they were exposed to ox-LDL (100 mg/L) for 48 hours;another group of cells were pretreated with antisense to 0.5 μmol/L LOX-1 mRNA or 0.5 μmol/L sense for 24 hours,and then HUVECs were exposed to ox-LDL (100 mg/L) for 12 hours. Apoptosis was assessed by the apoptosis ratio,cell viability,and Bcl-2/Bax ratio. Results As compared to untreated controls,pretreatment with rhEPO led to increased cell survival of HUVECs and decreased cell apoptosis in a dose-dependent manner (all P<0.05). Consistently,the Bcl-2/Bax ratios were also increased in a similar fashion. The ratio of apoptosis protein Bcl-2/Bax was increased in the antisense LOX-1 mRNA group than that of ox-LDL group (P<0.05),but the one in the sense LOX-1 mRNA group was not significantly different from that of ox-LDL group. Conclusion The ox-LDL can induce apoptosis in HUVECs by regulating LOX-1 mRNA,and rhEPO can increase Bcl-2/Bax ratio and inhibite ox-LDL-induced apoptosis of HUVECs.