GnRH Transactivates Human AMH Receptor Gene via Egr1 and FOXO1 in Gonadotrope Cells
GnRH Transactivates Human AMH Receptor Gene via Egr1 and FOXO1 in Gonadotrope Cells
复制标题
DOI：
10.1159/000494890
复制
发表时间：
2019-01-01
影响因子：
4.1
通讯作者：
Cohen-Tannoudji, Joelle
中科院分区：
文献类型：
--
作者：
Garrel, Ghislaine;Denoyelle, Chantal;Cohen-Tannoudji, Joelle
背景/目的：抗苗勒管激素（AMH）信号传导对性分化和性腺功能至关重要。AMH受体2型（AMHR 2）表达于性腺外部位，如脑和垂体，新的证据表明AMH的生物学作用比最初认为的要广泛得多。我们最近报道AMH信号增强垂体促性腺激素细胞中促卵泡激素的合成。然而，调节AMHR 2在这些性腺外位点的表达的机制仍有待探索。方法/结果：在这里，我们证明了灌流的小鼠L β T2促性腺细胞，Amhr 2的表达差异调节GnRH脉冲频率与高GnRH脉动下的诱导。此外，我们发现GnRH反式激活L β T2细胞中的人AMHR 2启动子。启动子的连续缺失揭示了含有Egr 1结合位点的短近端区域（-53/-37 bp）的重要性。利用定点突变Egr 1基序和siRNA介导的Egr 1敲低，我们证明了Egr 1介导的基础和GnRH依赖的启动子的活动，确定Egr 1作为一个新的转录因子控制hAMHR 2的表达。我们还表明，SF 1和β-连环蛋白是必需的基础启动子活性，并证明这两个因素有助于GnRH刺激作用，独立于其各自的结合位点。此外，使用FOXO 1的组成型活性突变体，我们确定FOXO 1作为基础和GnRH依赖性AMHR 2在促性腺细胞中表达的负调节因子。结论：这项研究确定了GnRH作为人类AMHR 2表达的调节因子，进一步强调了AMH信号在调节促性腺激素功能中的重要性。(c)2018 S. Karger AG，巴塞尔
Background/Objectives: Anti-Mullerian hormone (AMH) signaling is critical for sexual differentiation and gonadal function. AMH receptor type 2 (AMHR2) is expressed in extragonadal sites such as brain, and pituitary and emerging evidence indicates that AMH biological action is much broader than initially thought. We recently reported that AMH signaling enhances follicle-stimulating hormone synthesis in pituitary gonadotrope cells. However, mechanisms regulating AMHR2 expression in these extragonadal sites remain to be explored. Method/Results: Here, we demonstrated in perifused murine L beta T2 gonadotrope cells that Amhr2 expression is differentially regulated by GnRH pulse frequency with an induction under high GnRH pulsatility. Furthermore, we showed that GnRH transactivates the human AMHR2 promoter in L beta T2 cells. Successive deletions of the promoter revealed the importance of a short proximal region (-53/-37 bp) containing an Egr1 binding site. Using site-directed mutagenesis of Egr1 motif and siRNA mediated-knockdown of Egr1, we demonstrated that Egr1 mediates basal and GnRH-dependent activity of the promoter, identifying Egr1 as a new transcription factor controlling hAMHR2 expression. We also showed that SF1 and beta-catenin are required for basal promoter activity and demonstrated that both factors contribute to the GnRH stimulatory effect, independently of their respective binding sites. Furthermore, using a constitutively active mutant of FOXO1, we identified FOXO1 as a negative regulator of basal and GnRH-dependent AMHR2 expression in gonadotrope cells. Conclusions: This study identifies GnRH as a regulator of human AMHR2 expression, further highlighting the importance of AMH signaling in the regulation of gonadotrope function. (c) 2018 S. Karger AG, Basel