干扰Sestrin2表达对ox-LDL诱导的人脐静脉内皮细胞凋亡的影响

目的观察干扰Sestrin2表达对氧化型低密度脂蛋白(ox-LDL)诱导的人脐静脉内皮细胞(HUVEC)凋亡的影响。方法用ox-LDL处理HUVEC复制内皮细胞损伤模型。Western blot检测不同浓度ox-LDL处理HUVEC不同时间Sestrin2的蛋白表达水平及转染Sestrin2 siRNA后Sestrin2的蛋白表达水平;流式细胞术检测干扰Sestrin2表达后对ox-LDL诱导的HUVEC凋亡率的影响;Western blot检测干扰Sestrin2表达后对ox-LDL诱导的HUVEC中Caspase-3表达的影响及ox-LDL对HUVEC中JNK通路的影响。结果不同浓度(20、50和100 mg/L)的ox-LDL处理HUVEC 24 h均能明显上调Sestrin2表达;50 mg/L ox-LDL处理HUVEC不同时间(24 h和48 h)均能明显上调Sestrin2表达,24 h达高峰;转染Sestrin2 siRNA能明显抑制Sestrin2的表达;ox-LDL能明显诱导HUVEC凋亡,转染Sestrin2 siRNA能明显促进由ox-LDL诱导的HUVEC凋亡;ox-LDL能明显诱导p-JNK和p-c-Jun的表达,且SP600125能明显抑制由ox-LDL诱导的Sestrin2表达。结论 ox-LDL通过JNK/c-Jun信号通路诱导Sestrin2表达,干扰Sestrin2表达能明显促进ox-LDL诱导的HUVEC凋亡。

Effects of Sestrin2 Inhibition on Human Umbilical Vein Endothelial Cells Apoptosis Induced by ox-LDL

Aim To investigate the effect of Sestrin2 inhibition on apoptosis of human umbilical vein endothelial cells induced by oxidized low density lipoprotein (ox-LDL). Methods The cell injury model was induced by ox-LDL. Western blot was used to detect protein expression of Sestrin2 in human umbilical vein endothelial cells treated with different concentrations of ox-LDL at different time. Protein expression of Sestrin2 was observed by Western blot after transfection with Sestrin2 siRNA. Human umbilical vein endothelial cells were transfected with Sestrin2 siRNA, then treated with ox-LDL, cell apoptosis was detected by flow cytometry, Caspase-3 expression and JNK pathway were observed by Western blot. Results Sestrin2 expression was significantly induced after treatment at different concentrations (0,0 and 100 mg/L) of ox-LDL for 24 h. Moreover, human umbilical vein endothelial cells were incubated with 50 mg/L ox-LDL for various periods of time ranging from 0 to 48 h. The results showed a significant increase of Sestrin2 at protein levels in 24 h and 48 h, and it was the highest level in 24 h. Transfection with Sestrin2 siRNA significantly inhibited Sestrin2 expresssion. ox-LDL significantly induced cell apoptosis, transfection with Sestrin2 siRNA increased the effect. Expression of p-JNK and p-c-Jun was induced by ox-LDL, and this effect could be inhibited by SP600125. Conclusions Ox-LDL induces Sestrin2 expression through JNK/c-Jun pathway, inhibition of Sestrin2 expression significantly increases human umbilical vein endothelial cells apoptosis induced by ox-LDL.