葡萄糖对内皮细胞内皮抑素表达的影响(英文)

Effect of glucose on endostatin expression in human vascular endothelial cells

目的研究不同浓度葡萄糖作用下人内皮细胞内皮抑素( endostatin, ES) 的代谢特点, 探索内皮抑素与糖尿病血管病变的关系。方法培养人脐静脉内皮细胞( HUVECs) , 随机加入不同浓度的葡萄糖液中培养,分为正糖对照组( 5.6 mmol/L Glu) , 高糖组( 11.2 mmol/L Glu、22.4 mmol/L Glu 组) 。培养 24、48、72 和 96h后, 收集各组不同作用时间点的 HUVECs, 采用 RT- PCR 法检测 ES mRNA 的表达, Western- blot 法检测 ES蛋白水平的表达。结果 11.2 mmol/L Glu 组, ES mRNA 和蛋白的表达随着时间的延长而增强, 第 72、96 小时表达水平显著高于对照组( P 72h<0.05, P 96h<0.01) ; 22.4 mmol/L Glu 组, ES mRNA 和 ES 蛋白的表达在 24、48、72h随着时间的延长而增强, 72 h 表达水平显著高于对照组( P <0.05) , 而 96 h 表达水平明显低于对照组( P <0.05) ; 对照组中 ES mRNA 的表达水平不随时间的延长而改变, ES 蛋白的表达水平随着时间的延长逐渐降低,96h 的表达水平明显低于 24 h 的( P <0.05) 。结论高糖对 HUVECs中 ES mRNA 和蛋白表达水平的影响是双向的: 短时间内起促进作用, 具有时间依赖性; 随着作用时间的延长, 高糖对 ES mRNA 和蛋白的表达转为抑制; 在 DM 慢性长期病程中, ES 表达的降低可能与 DM 血管病变的发生有关。

[Objective] To study the influence of glucose concentration on expression of endostatin mRNA and protein in cultured human umbilical vein endothelial cells （HUVECs）, to demonstrate the characteristics of endostatin （ES） metabolism in high glucose, and thus to explore the possibility of ES to retard the progress of vascular disease complicated with DM. [Methods] HUVECs were cultured in DEME media with or without high glucose and were divided into 3 groups randomly： control group （with 5.6 mmol/L Glu）, high glucose groups （with 11.2, 22.4 mmol/L Glu, respectively）. After 24, 48, 72 and 96 hours, total RNA and protein were extracted. Semi-quantative RT-PCR and Western blot were used to detect the expression of ES. [Results] The level of ES expression in HUVECs treated with 11.2 mmol/L Glu was increasing with prolonged exposure time at both mRNA and protein levels, especially when the exposure time reached 72 and 96 hours, there was a significant increase compared with control group （P 72 h〈0.05, P 96 h〈0.01）. When HUVECs were treated with 22.4 mmol/L Glu for 24, 48 and 72 hours, both gene and protein expression of endostatin increased in a time-dependent manner. There was a significant increase in ES expression when they were incubated for 72 hours, but a significant decrease for 96 hours compared with control group （P 〈0.05）. For control group, there was a significant decrease in protein release of ES incubated for 96 hours compared with those for 24 hours （P 〈0.05）, but there was no significant change in expression of ES mRNA during the observed period. [Conclusions] For certain limited period, the expression of endostatin is induced in a time-dependent manner in HUVECs cultured with high concentration of glucose, but it is suppressed with prolonged exposure time. And the reduction in ES expression at both mRNA and protein levels may be part of the reason for those vascular diseases complicated with DM chronically.