Identification of an Enhancer in the Ad4BP/SF-1 Gene Specific for Fetal Leydig Cells
Identification of an Enhancer in the Ad4BP/SF-1 Gene Specific for Fetal Leydig Cells
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DOI：
10.1210/en.2011-1407
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发表时间：
2012-01-01
期刊：
影响因子：
4.8
通讯作者：
Morohashi, Ken-ichirou
中科院分区：
文献类型：
--
作者：
Shima, Yuichi;Miyabayashi, Kanako;Morohashi, Ken-ichirou
肾上腺素4结合蛋白/类固醇生成因子1（Ad 4 BP/SF-1）（Nr 5a 1）是生殖组织发育和内分泌调节所必需的核受体。该因子在类固醇生成组织中表达（例如，G.肾上腺和性腺），并且该因子的表达以组织和细胞类型特异性的方式被严格调节。我们以前的研究已经确定了组织和细胞类型特异性增强子的Ad 4 BP/SF-1基因的内含子在胎儿肾上腺，腹内侧下丘脑，垂体促性腺激素。增强子的表征为组织和细胞发育提供了新的见解。然而，这些研究未能确定任何性腺特异性增强子。在这里，我们确定了胎儿Leydig细胞特异性增强子的上游区域的小鼠Ad 4 BP/SF-1基因使用转基因小鼠试验。脊椎动物物种之间的上游区域的比对表明，增强子由三个保守区域组成，其中最高度保守的区域含有Ad 4 BP/SF-1结合序列和E-box。每个序列的突变消除了增强子活性，并导致报告基因表达的损失。这些结果表明，Ad 4 BP/SF-1基因在胎儿Leydig细胞中的表达受到尚未鉴定的E-box结合蛋白和Ad 4 BP/SF-1形成的自动调节环的调节。虽然胎儿间质细胞被认为通过雄激素的产生在各种胎儿组织的男性化中发挥着至关重要的作用，但其他功能仍然难以捉摸。我们在Ad 4 BP/SF-1基因中鉴定胎儿间质细胞特异性增强子将是解决知识库中这些空白的有力工具。（内分泌学153：417-425，2012）
Adrenal 4 binding protein/steroidogenic factor 1 (Ad4BP/SF-1) (Nr5a1) is a nuclear receptor essential for reproductive tissue development and endocrine regulation. This factor is expressed in steroidogenic tissues (e. g. adrenal glands and gonads), and expression of this factor is tightly regulated in a tissue and cell type-specific manner. Our previous studies have identified tissue and cell type-specific enhancers in the introns of the Ad4BP/SF-1 gene in fetal adrenal glands, ventromedial hypothalamus, and pituitary gonadotrope. Characterization of the enhancers had provided new insights into tissue and cell development. However, these studies have failed to identify any gonad-specific enhancer. Here, we identified a fetal Leydig cell-specific enhancer in the upstream region of the mouse Ad4BP/SF-1 gene using transgenic mouse assays. Alignment of the upstream regions among vertebrate animal species demonstrated that the enhancer consisted of three conserved regions, whereby the most highly conserved region contained an Ad4BP/SF-1 binding sequence and an E-box. Mutation of each sequence abolished the enhancer activity and led to a loss of reporter gene expression. These results suggested that Ad4BP/SF-1 gene expression in the fetal Leydig cell is regulated by a yet unidentified E-box binding protein(s) and by an autoregulatory loop formed by Ad4BP/SF-1. Although fetal Leydig cells have been thought to play crucial roles for masculinization of various fetal tissues through androgen production, other functions have remained elusive. Our identification of a fetal Leydig cell-specific enhancer in the Ad4BP/SF-1 gene would be a powerful tool to address these gaps in the knowledge base. (Endocrinology 153: 417-425, 2012)