大剂量糖皮质激素下调血管内皮细胞GR表达的意义

目的观察LPS和Dex对人脐静脉内皮细胞糖皮质激素受体(GR)的表达情况。方法利用内毒素脂多糖LPS"致伤"血管内皮细胞,用地塞米松进行"治疗",然后通过RT-PCR和免疫组化的方法检测血管内皮细胞糖皮质激素受体(GR)的表达情况。结果内皮细胞本身能明显表达GRmRNA,运用不同浓度Dex和100 ng/ml LPS刺激后,可使人脐静脉内皮细胞内GRmRNA表达明显下降,应用大剂量(10-6mol/L)的Dex刺激细胞3h,GRmRNA的表达无明显变化,6 h开始明显下降,12 h达高峰,24 h回升近刺激前水平。结论大剂量的Dex(10-6mol/L)可下调GR的表达,表明严重创伤时血管内皮细胞中糖皮质激素作用存在其他的作用机制。

Significance of down-regulation of the glucocorticoid receptor expression in vascular endothelial cells by high-dose of glucocorticoids

Objective To explore the expression of glucocorticoid receptor(GR) with lipopolysaccharide(LPS) and dexamethasone(Dex) in human umbilical vein endothelial cells and its mechanism.Methods LPS "injured" endothelial cells with dexamethasone for "treatment",and then the expression of glucocorticoid receptor(GR) in the endothelial cells was detected by RT-PCR and immunohistochemistry.Results Endothelial cells had some expressions of GRmRNA by itself,but the expression of GRmRNA significantly decreased with different dose of Dex and 100 ng/ml LPS.After the stimulation of high dose(10-6 mol/L) of Dex,GRmRNA had no significant changes in the expression at 3 h,but began to obviously decrease at 6 h,had a peak at 12 h,and then increased to the level that before stimulation.Conclusion Large dose of DEX(10-6 mol/L) can down-regulate the expression of GR,suggesting that a new regulatory mechanism may existed during the effect of GR on human umbilical vein endothelial cells in serious trauma.