地塞米松给药及撤药后糖皮质激素受体的表达 - 第三军医大学学报.doc

地塞米松给药及撤药后糖皮质激素受体的表达 (杨 玲，何 威，李 颖，张 斌 （第三军医大学附属新桥医院皮肤科，重庆 400037） 摘 要： 观察地塞米松对体外培养人皮肤角质形成细胞HaCaT细胞糖皮质激素受体（Glucocorticoid receptor, GR）α和β表达的调节以及撤去该药后GRα和GRβ基因表达的后续变化，并探讨其临床意义。方法 以含10-6mol/L地塞米松的DMEM（高糖）培养基孵育细胞，48h后换不含地塞米松的培养基继续孵育。在地塞米松给药后24h和48h以及撤药后24h、48h和72h的不同时相点，采用Real time PCR和Western blotting检测GRα和GRβ的表达变化，采用免疫荧光化学法观察GRα和GRβ的细胞内定位。结果 地塞米松给药后24h和48h，GRα的mRNA和蛋白质水平逐渐下降（P＜0.01），而GRβ的mRNA和蛋白质水平均逐渐上升（P＜0.05）；撤药后24h、48h和72h，GRα和GRβ的上述变化不同程度地向原有水平回复。结论 地塞米松以时间依赖性方式下调GRα并上调GRβ，可能部分解释持续外用糖皮质激素制剂后出现的“激素耐受”现象；下调的GRα和上调的GRβ在地塞米松撤药后以时间依赖性方式呈向其原有水平恢复的趋势，提示临床上外用激素治疗应避免长期使用。 关键词：糖皮质激素；糖皮质激素受体；角质形成细胞；地塞米松 Expression of glucocorticoid receptor under dexamethasone or after withdrawal YANG Ling, HE Wei, LI Yin, ZHANG Bin (Department of Dermatology, Xinqiao Hospital, The Third Military Medical University, Chongqing 400037, China) Abstract: Objectives To investigate the expression of glucocorticoid receptor (GR) α and β in cultured human keratinocytes (HaCaT cells) with treatment of dexamethasone (Dex) and after withdrawal of Dex. Methods GRα and GRβ mRNA and protein expression in HaCaT cells with treatment of Dex (10-6mol/L) and after withdrawal of Dex were detected by real time PCR and western blotting. The intracellular distribution of GRα and β was examined by immunofluorescence. Results 24h or 48h after treating Dex, the expression of GRα was reduced (P＜0.01, GRβ was increased (P＜0.0as shown by real time PCR and western blotting analysis. 24h, 48h and 72h after withdrawal of Dex, the above changes gradually recover to their previous levels. Conclusion Dex could down-regulate GRα and up-regulate GRβ in a time-dependent manner, which could partly explain the tachyphylaxis correlate to persistent application of topical glucocorticoids. After Dex was removed, both GRα and β could recover to their previous levels, which suggested long-term application of topical glucocorticoid should be avoided. Key words: glucocorticoids; glucocorticoid receptor; keratinocyte; dexamethasone 糖皮质