人endostatin体外诱导血管内皮细胞凋亡的实验研究

目的 探讨人endostatin抑制血管内皮细胞增殖的作用机制。方法 在含重组人endostatin蛋白和10%小牛血清的DMEM培养基中，培养人脐静脉内皮细胞ECV304。72h后，采用透射电镜，流式细胞术细胞周期分析和细胞核DNA的1.5%琼脂糖凝胶电泳，检测重组人endostatin蛋白作用后，血管内皮细胞的凋亡。结果 透射电镜下可见实验组ECV304细胞核染色质浓缩，边集，核碎裂及胞浆浓缩等，呈典型的凋亡细胞的形态学表现，流式细胞术细胞周期分析显示，在G1期峰前存在1个凋亡峰（20.6%)，1.5%琼脂糖凝胶电泳显示，细胞核DNA呈梯状，对照组ECV304细胞表达正常。结论 重组人endostatin蛋白可诱导血管内皮细胞凋亡，是其抑制血管内皮细胞增殖的原因之一。

Experimental study on apoptosis of vascular endothelial cell induced by endostatin in vitro

Aim To explore the mechanism underlying endostatin inhibition of the proliferation of vascular endothelial cells. Methods Human umbilical vein endothelial cells ECV304 were cultured in DMEM medium containing 10% FBS and recombinant endostatin protein for 72 h. Then the apoptosis of the ECV304 cells was detected by transmission electron microscope, flow cytometry and 1.5% agarose gel electrophoresis of nuclear DNA. Results Under the transmission electron microscope ECV304 cells treated with endostatin showed condensation and margination of nuclear chromatin, fragmentation of nuclears and condensation of cytoplasm which were typical manifestation of apoptosis. Flow cytometry showed a visible apoptotic peak (20.6%) in front of the G1 peak. The typical DNA ladder was found in the 1.5% agarose gel electrophoresis of the nuclear DNA. The control ECV304 cells did not show these apoptic characttristics. Conclusion The recombinant endostatin protein can induce the apoptosis of the vascular endothelial cells, which may be one of the reasons why it inhibits the proliferation of the endothelial cells.