PITUITARY CELL CULTURE: ESTROGEN CONTROL OF FSH

卵泡刺激素(FSH)，主要的营养激素 哺乳动物的卵子和精子的发育，是由两种蛋白质组成的 亚基，阿尔法和贝塔。荷尔蒙特异的β亚基是 垂体促性腺激素细胞的限制性亚基及其调节 在控制卵泡刺激素的产生方面显得至关重要。17β-雌二醇 (E)和孕酮(P)迅速减少FSH的分泌 绵羊、猪和人类的脑下垂体培养.羊的数据 表明E和P降低了两个亚单位mRNAs的转录 在2小时(测试版)和12小时(阿尔法版)内增加85%。我们建议 定义FSHβ亚基基因上的DNA序列 介导E和P诱导的抑制。这些序列可能是 引起类固醇受体结合位点的负性调节 抄写。新合成的蛋白质似乎并不起中介作用 FSH抑制，因为抑制作用不被环己酰亚胺改变。 与阴性有关的生物功能序列 监管将由他们授予E-和P-P的能力来定位- 报告基因在瞬变过程中的依赖调节 类固醇敏感的人绒毛膜癌细胞系中的表达 (JAR单元格)。这些细胞自然表达两种促性腺激素基因。 与FSHβ(α和hCGβ)有关，它们可以使E- 通过转染表达迷你基因的质粒进行应答 编码E受体；表达P的类似质粒 感受器很快就会上市。富含初级绵羊 促性腺激素细胞也将被开发为可能的替代品， 或与JAR细胞一起用于研究负性类固醇 监管。E或P以外的其他蛋白质的参与 受体，在负的类固醇作用，将通过检查 细胞蛋白与E和P沉默DNA的结合。我们的研究 是为了更好地了解负性基因 哺乳动物的监管(这是一个知之甚少的领域，部分 由于缺乏模型系统来研究)和2)E的行为 和P是重要的，因为它们在 生殖，它们明显参与转录 某些肿瘤的调节剂及其作为类固醇模型的应用 荷尔蒙作用。对卵泡刺激素β亚基的调控研究 同样重要的是，它们定义了控制 FSH的合成/分泌，因此，性腺功能和 生育能力。

Follicle stimulating hormone (FSH), the primary trophic hormone for egg and sperm development in mammals, is composed of two protein subunits, alpha and beta. The hormone-specific beta subunit is the limiting subunit in pituitary gonadotrophs and its regulation appears paramount in controlling FSH production. 17 beta-Estradiol (E) and progesterone (P) rapidly decrease secretion of FSH from pituitary cultures of sheep, pigs, and humans; data from sheep indicate that E and P decrease transcription of both subunit mRNAs by > 85% within 2 hr (beta) and 12 hr (alpha). We propose to define those DNA sequences on the FSH beta subunit gene that mediate E- and P-induced inhibition. These sequences may be steroid receptor binding sites which cause negative regulation of transcription. Newly synthesized proteins do not seem to mediate FSH inhibition because inhibition is not altered by cycloheximide. Biologically functional sequences responsible for negative regulation will be located by their abilities to confer E- and P- dependent regulation upon reporter genes during their transient expression in a steroid-responsive human choriocarcinoma cell line (JAR cells). These cells naturally express two gonadotrophin genes related to FSH beta (alpha and hCG beta) and they can be made E- responsive by transfection with plasmids that express minigenes coding for the E receptor; similar plasmids for expressing P receptors will be available soon. Enriched primary ovine gonadotrophs will also be developed as a possible alternative to, or companion with, JAR cells for studying negative steroid regulation. The involvement of proteins, other than E or P receptors, in negative steroid action will be studied by examining binding of cellular proteins to E and P silencer DNA. Our studies are designed to gain a better understanding of 1) negative gene regulation in mammals (an area which is poorly understood, partly due to a lack of model systems to study) and 2) the actions of E and P which are important because of their essential roles in reproduction, their apparent involvement as transcriptional regulators of certain tumors, and their use as a model for steroid hormone action. Regulatory studies on the FSH beta subunit are also important because they define critical factors in controlling FSH synthesis/secretion and, therefore, gonadal function and fertility.