活化蛋白C对脂多糖诱导的人脐静脉血管内皮细胞凋亡的影响研究

目的：观察不同剂量活化蛋白C(APC)对脂多糖(LPS)诱导的人脐静脉血管内皮细胞（HUVECs）凋亡的作用。方法:将培养成功的HUVECs通过LPS（1 mg/L）孵育诱导细胞凋亡模型，并给予APC（10 μg/L）或APC（50 μg/L）建立药物治疗组，同时设立正常对照细胞组和单独LPS（1 mg/L）诱导细胞凋亡组。应用电镜观察细胞超微结构；DNA ladder与TUNEL荧光染色法检测细胞凋亡情况；Annexin-Ⅴ/PI双标记行流式细胞仪测定定量观察细胞凋亡率。同时采用MTT法测定细胞存活率和Western blotting测定增殖细胞核抗原（PCNA），以观察细胞的增殖变化。结果:通过细胞形态，DNA ladder和TUNEL荧光染色发现单独LPS诱导组的细胞可见明显的凋亡现象，而通过APC治疗组的细胞凋亡改变明显减轻和细胞凋亡率下降，同时细胞存活率和PCNA表达率增高，尤其在50 μg/L时，与单独LPS诱导组细胞比较差异显著（P<0.05）。结论:APC拮抗LPS诱导的血管内皮细胞凋亡并促进细胞的增殖，发挥保护细胞的作用。

Effect of activated protein C on apoptosis in human umbilical vein endothelial cells induced by lipopolysaccharide

AIM:To study the effect of activated protein C (APC) at different concentrations on apoptosis of human umbilical vein endothelial cells (HUVECs) induced by lipopolysaccharide (LPS).METHODS:The HUVECs were induced by LPS (1.0 mg/L) as apoptotic model that was administered by different concentration of APC (10 μg/L or 50 μg/L). Meanwhile, the control group and induced apoptosis group induced by LPS (1.0 mg/L) stimulation were also set up. The changes of cellular ultrastructures were observed under electron microscope. The DNA ladder and TUNEL fluorescent staining were measured in cells. Annexin-Ⅴ/PI double staining was used to measure the cell apoptosis rate by flow cytometry. Cell survival rate was measured by MTT assay. The proliferating cell nuclear antigen (PCNA) expression levels in cells were also measured by Western blotting to reflect the proliferation of the cells.RESULTS:There were significant apoptotic changes in the cells induced by LPS, but the apoptotic changes were reduced and apoptosis rates were decreased in the cells treated with APC. Meanwhile, cell survival rate and the protein levels of PCNA were increased after APC treatment, particularly at the concentration of 50 μg/L, which showed difference when compared with those induced apoptosis group by LPS (P<0.05).CONCLUSION:APC can inhibit HUVECs apoptosis induced by LPS and promote cell proliferation, thus protect the cells from injury.