低密度脂蛋白对高糖状态下血管内皮细胞脂质过氧化物和细胞间黏附分子-1的影响

The effects of low-density lipoprotein on lipoperoxide and ICAM-1 in vascular endothelial cells under high glucose condition

目的:观察高糖状态下低密度脂蛋白(LDL)对体外培养的血管内皮细胞(ECV-304)脂质过氧化物(LPO)代谢变化中丙二醛(MDA)和细胞间黏附分子-1(ICAM-1)分泌的影响。方法:不同浓度(5.5、20mmol/L)葡萄糖(Glu)的培养液细胞中,分别加入不同浓度LDL(0、50、100μg/mL)进行氧化损伤48h,采用倒置显微镜观测细胞形态学、MTT法检测细胞活性、硫代巴比妥酸(TBA)法测定MDA的含量、细胞ELISA法测定ICAM-1的分泌。结果:(1)高糖状态下ECV-304细胞脂质过氧化的量明显增加(P<0.05或P<0.0者),加入LDL后,MDA含量显著增加,脂质过氧化损伤显著加重,表现出明显协同作用(P<0.05或P<0.01)。(2)高糖状态下高浓度LDL抑制内皮细胞的活力(P<0.05),且呈浓度依赖性;(3)高浓度Glu和LDL具有正协同作用,促进ICAM-1的分泌。结论:高浓度Glu和LDL对血管内皮细胞具有协同损伤作用,高糖状态下LDL可直接导致内皮细胞损伤,引起ICAM-1产生增多,促进糖尿病血管并发症的发生、发展。

Objective To explore the effects of low-density lipoprotein （LDL） on MDA in lipoperoxide metabolism and the secretion of ICAM-1 in vascular endothelial cells （ECV-304） under high glucose condition. Methods ECV-304 cells were cultured with glucose in different concentrations （5.5 and 20 mmol/L）, and then oxidated for 48 h with LDL in various concentrations （0, 50, and 100 μg/mL）. MTr assay was used to detect the cell activity, TBA to measure the MDA content, and ELISA to determine the ICAM-1 secretion. Results （1） A significant elevation in lipoperoxidation of the cells occurred under high glucose condition （P 〈 0.05 or P 〈 0.01） and the MDA content and lipoperoxidation were markedly increased after the cells were treated with LDL, showing a synergetic action of high glucose and LDL level（P 〈 0.05 or P 〈 0.01）. （2） High LDL level inhibited the cell activity in a concentration-dependent manner under high glucose condition （P 〈 0.05）. （3） Glucose and LDL in high concentration had a synergetic effect on stimulating the ICAM-1 secretion. Conclusions High concentrations of glucose and LDL play a synergetic role in damage to the endothelial ceils. LDL can directly lead to the endothelial cell injury and enhance the ICAM-1 secretion, which accelerates the development of diabetic vascular complications.