Estrogen: Roles in spermatogenesis
Estrogen: Roles in spermatogenesis
复制标题
DOI：
10.2174/187152208783790679
复制
发表时间：
2008-03-01
期刊：
影响因子：
--
通讯作者：
Lambard, Sophie
中科院分区：
文献类型：
--
作者：
Carreau, Serge;Bourguiba, Sonia;Lambard, Sophie
在哺乳动物睾丸中，雄激素向雌激素的不可逆转化由细胞色素P450芳香化酶催化，细胞色素P450芳香化酶是一种微粒体酶复合物，由人类独特基因（Cyp 19）编码，含有18个外显子，其中9个外显子被翻译。此外，该基因包括9个非编码外显子I，位于5'端并由组织特异性启动子控制，所述启动子选择性地剪接到外显子II中的共同位点上。然而，产生了55 kDa的独特蛋白质。在迄今为止研究的大多数哺乳动物中，至少在啮齿动物中，除了管周细胞之外的所有睾丸细胞都含有芳香酶，因此芳香酶根据体细胞和生殖细胞来源组成型表达并且非常精确地控制（在表达和酶活性方面）。在人类中，我们从射精精子和未成熟的宝石细胞获得的数据表明存在生物活性芳香酶;此外，雌激素受体（ER α和ER β）也存在，特别是在曲细精管中的ER。根据芳香化酶和雌激素受体在睾丸细胞中的广泛定位，我们的综述清楚地表明，除了促性腺激素和雄激素，雌激素产生的本地，应被视为生理相关的激素参与精子发生和精子发生的调节。因此，芳香化酶可能是一个有用的标志物，它可能反映在精子发生过程中的基因表达以及精子质量，因此，该参数可用作诊断工具，以评估在男人的生育能力。
In the mammalian testis, the irreversible conversion of androgens into estrogens is catalyzed by the cytochrome P450 aromatase, a microsomal enzymatic complex encoded by a unique gene ( Cyp19) in humans which contained 18 exons, 9 of them being translated. In addition that gene includes 9 non-coding exons I, located in the 5' end and controlled by tissue-specific promoters that are spliced alternatively onto a common site in exon II. However, a unique protein of 55 kDa is produced. In most of mammals studied so far, at least in rodents, all testicular cells except peritubular cells contain aromatase which is therefore constitutively expressed and very precisely controlled (in terms of expression and enzyme activity) according to somatic and germ cell origin. In man, our data obtained from both ejaculated spermatozoa and immature gem cells demonstrate the presence of a biologically active aromatase; moreover estrogen receptors (ER alpha and ER beta) are also present, especially ER in seminiferous tubules. All together according to the widespread localisation of aromatase and estrogen receptors in testicular cells, our review clearly shows that besides gonadotrophins and androgens, estrogens produced locally, should be considered as physiologically relevant hormones involved in the regulation of spermatogenesis and spermiogenesis. Therefore it is suggested that aromatase could be a helpful marker which might reflect the gene expression during spermatogenesis as well as the sperm quality and consequently, that parameter may be used as a diagnostic tool to assess the fertility in man.