糖皮质激素受体基因中的两个多态性直接影响糖皮质激素调节的基因表达。

Two polymorphisms in the glucocorticoid receptor gene directly affect glucocorticoid-regulated gene expression.

作者信息

Russcher Henk, Smit Pauline, van den Akker Erica L T, van Rossum Elisabeth F C, Brinkmann Albert O, de Jong Frank H, Lamberts Steven W J, Koper Jan W

机构信息

Erasmus Medical Center, Department of Internal Medicine, Room Ee593, Dr. Molewaterplein 40, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands.

出版信息

J Clin Endocrinol Metab. 2005 Oct;90(10):5804-10. doi: 10.1210/jc.2005-0646. Epub 2005 Jul 19.

DOI:10.1210/jc.2005-0646

PMID:16030164

Abstract

CONTEXT

Interindividual variation in glucocorticoid (GC)-sensitivity can be partly explained by polymorphisms in the GC receptor (GR) gene. The ER22/23EK and N363S polymorphisms have been described to be associated with lower and higher GC sensitivity, respectively.

OBJECTIVE AND DESIGN

We examined the basis of this altered GC sensitivity by expressing GR(N363S) and GR(ER22/23EK) in COS-1 cells and investigating their transactivating and transrepressing capacities using a GC response element-luciferase reporter and a p65-activated nuclear factor kappaB-luciferase reporter, respectively. Furthermore, we evaluated the transactivating and transrepressing capacities of the GR in peripheral blood mononuclear lymphocytes of homozygous and heterozygous carriers of these polymorphisms by determining the maximum effect of dexamethasone on transactivation of the GC-induced leucine-zipper and transinhibition of the IL-2 gene by means of real-time RT-PCR.

RESULTS

The effects of the polymorphisms in the GR gene previously observed in population studies were also detected at the level of gene expression. The ER22/23EK polymorphism resulted in a significant reduction of transactivating capacity, in both transfection experiments (-14 +/- 5%, P < 0.05) and peripheral blood mononuclear lymphocytes of carriers of this polymorphism (homozygous: -48 +/- 6%, P < 0.01, n = 1; heterozygous: -21 +/- 4%, P = 0.08, n = 3). The N363S polymorphism, associated with increased GC sensitivity, resulted in a significantly increased transactivating capacity, both in vitro (8 +/- 3%; P < 0.02) and ex vivo (homozygous: 204 +/- 19%, P < 0.0001, n = 1; heterozygous: 124 +/- 8%, P = 0.05, n = 3). Neither the ER22/23EK nor the N363S polymorphism seemed to influence the transrepressing capacity of the GR.

CONCLUSION

The presence of these and other GC sensitivity-modulating polymorphisms may have consequences for the use of GCs in a clinical setting.

摘要

背景

糖皮质激素（GC）敏感性的个体间差异部分可由糖皮质激素受体（GR）基因的多态性来解释。据描述，ER22/23EK和N363S多态性分别与较低和较高的GC敏感性相关。

目的与设计

我们通过在COS-1细胞中表达GR（N363S）和GR（ER22/23EK），并分别使用GC反应元件荧光素酶报告基因和p65激活的核因子κB荧光素酶报告基因来研究它们的反式激活和反式抑制能力，从而探究这种GC敏感性改变的基础。此外，我们通过实时逆转录聚合酶链反应确定地塞米松对GC诱导的亮氨酸拉链的反式激活和IL-2基因的反式抑制的最大效应，来评估这些多态性的纯合子和杂合子携带者外周血单核淋巴细胞中GR的反式激活和反式抑制能力。

结果

在群体研究中先前观察到的GR基因多态性的影响在基因表达水平也被检测到。ER22/23EK多态性导致反式激活能力显著降低，在转染实验中（-14±5%，P<0.05）以及该多态性携带者的外周血单核淋巴细胞中（纯合子：-48±6%，P<0.01，n = 1；杂合子：-21±4%，P = 0.08，n = 3）。与GC敏感性增加相关的N363S多态性导致反式激活能力显著增加，在体外（8±3%；P<0.02）和体内（纯合子：204±19%，P<0.0001，n = 1；杂合子：124±8%，P = 0.05，n = 3）。ER22/23EK和N363S多态性似乎都不影响GR的反式抑制能力。