内皮抑制素抑制内皮细胞增殖的细胞周期调控机制

Molecular mechanism of endothelial cell growth arrest by endostatin

目的 探讨内皮抑制素 (endostatin)抑制内皮细胞增殖的细胞周期调控机制。方法 将ECV 3 0 4细胞分为对照组、碱性成纤维细胞生长因子 (bFGF ,10 μg/L) 处理组、endostatin(10mg/L)处理组。检测ECV 3 0 4体外生长情况及细胞周期分布 ,观察细胞周期蛋白依赖激酶 4(CDK 4)、cyclinD1、p2 1、p2 7表达。 结果 bFGF处理后 ,ECV 3 0 4G0 /G1期细胞由 5 7%减少至3 7% ,而S期、G2 /M期细胞增多。加入endostatin后 ,G0 /G1期细胞增多至 5 4% ,S期、G2 /M期细胞增多 ;bFGF刺激后 ,ECV 3 0 4细胞内cyclinD1、CDK4表达增强 ,p2 1、p2 7表达无明显变化。加入endostatin后 ,cyclinD1、CDK4表达减弱 ,p2 1表达增强 ,p2 7无明显表达。 结论 endostatin可能通过上调 p2 1表达 ,抑制cyclinD1/CDK4表达 ,阻止内皮细胞G1→S期进程 。

Objective To investigate the effect of endostatin on endothelial cell cycle.Methods Human umbilical vein endothelial cell line ECV-304 cells was treated with 10 μg/L bFGF and 10 mg/L endostatin.The cell growth was observed by using MTT method.Flow cytometry and immunochemistry were applied to observe the effects of endostatin on cell cycle and the expression of CDK 4,cyclinD1,p21,p27 in ECV-304 cells in vitro.Results Endostatin could inhibit the growth of ECV-304 cells induced by bFGF.bFGF could decrease G 0/G 1 stage cells,increase S and G 2/M stage cells of ECV-304 cells.Addition of endostatin could increase G 0/G 1 stage cells,and decrease S,G 2/M stage cells of ECV-304 cells.Endostatin could increase the p21 expression,and decrease the cyclinD1/CDK4 expression in ECV-304 cells.Conclution The increased p21 expression and inhibited cyclinD1/CDK4 expression by endostatin may decrease the number of cells entering S stage (G 1 arrest),which induces inhibition of bFGF-induced proliferation of endothelial cells.