地塞米松对血管内皮细胞11β-HSD1基因表达的影响

Effect of dexamethasone on the expression of 11β-HSD1 in vascular endothelial cells

目的探讨地塞米松(Dex)对血管内皮细胞11β羟基类固醇脱氢酶1(11β-HSD1)mRNA表达的影响,以及p38丝裂原活化蛋白激酶(p38MAPK)和糖皮质激素(GC)受体在其中所起的作用。方法先给予不同浓度(10-9、10-8、10-6、10-5、10-3mol/L)的Dex与血管内皮细胞共同培养24h,应用RT-PCR测定各浓度组中11β-HSD1 mRNA水平,其中不接触Dex的细胞为正常对照组;采用p38MAPK特异性抑制剂SB203580(10-2mol/L)及GC受体特异性抑制剂RU486(10-6mol/L)与细胞作用2h后,再加入Dex(10-6、10-3mol/L)作用24h,RT-PCR测定11β-HSD1 mRNA水平,其中仅用Dex处理的细胞作为阴性对照组,不加干扰因素的细胞作为正常对照组。结果Dex(10-9、10-8、10-6、10-5、10-3mol/L)各个浓度组中11β-HSD1 mRNA/β-actin mRNA(分别为0.120±0.040、0.140±0.020、0.280±0.030、0.360±0.060、0.460±0.040)均不同程度高于正常对照组(0.030±0.004,P<0.05),并且与Dex浓度呈剂量依赖性。在不同浓度Dex(10-6、10-3mol/L)处理的细胞中,SB20358组中11β-HSD1 mRNA/β-actin mRNA值(分别为0.28±0.03、0.46±0.04)与阴性对照组(分别为0.28±0.03、0.46±0.04)相比没有显著性差异(P>0.05);而RU486组中11β-HSD1 mRNA/β-actin mRNA值(分别为0.21±0.02、0.36±0.05)与阴性对照组相比显著降低(P<0.05)。结论Dex可能部分通过GC受体诱导11β-HSD1基因转录增强,而与p38MAPK通路的激活无关。

Objective To investigate the effect of dexamethasone （Dex） on the transcription of 11 β-hydroxysteroid dehydrogenase type 1 （11β-HSD1） gene in vascular endothelial cells. The roles of p38 mitogen-activated protein kinase （p38MAPK） signaling pathway and glucocorticoid receptor （GR） were also observed. Methods Vascular endothelial cells were co-cultured with different concentrations of Dex （10^-9 -10^3mol/L） for 24h. Reverse transcription polymerase chain reaction （RT-PCR） was employed to detect 11β-HSD1 mRNA in each group. Normally cultured cells, without contact with Dex, served as normal control group. The cells were co-cultured with p38MAPK specific inhibitor SB20358 （10^-2mol/L） and GR specific inhibitor RU486 （10^-6mol/L） for 24h, then RT PCR was employed to detect 11β-HSD1 rnRNA in each group. Among the groups, Dex-treated cells and non-intervened cells were grouped as negative control and normal control, respectively. Results 11β-HSD1 rnRNA/β-actin mRNA of Dex-treated groups （respectively as 0. 120±0. 040, 0. 140 ±0. 020, 0. 280±0. 030, 0. 360±0. 060, 0. 460±0. 040） were significantly higher than that of the normal control （0. 030±0. 004, P〈 0.05） depending on the Dex concentration. Among those cells co-cultured with different concentrations of dexamethasone （10^-6, 10^-3 mol/ L）, 11β-HSD1 mRNA/β-actin mRNA of SB203580 group （respectively as 0. 28±0. 03, 0. 46±0. 04） had no statistically significant differences with the negative group （respectively as 0. 28±0. 03, 0. 46±0. 04）, while the values of 11β-HSD1 mRNA/β-actin mRNA in the RU486 group （respectively as 0. 21 ± 0. 02, 0. 36±0. 05） were remarkably lower than that of the negative group （P〈0. 05）. Conclusion It is suggested that dexamethasone, without activation of p38MAPK pathway, may enhance the transcription of 11β-HSD1 gene in vascular endothelial cells partly by the aid of glucocorticoid receptor.