PITUITARY CELL CULTURE: ESTROGEN CONTROL OF FSH

卵泡刺激素（FSH），主要的营养激素， 在哺乳动物的卵子和精子发育过程中，是由两种蛋白质组成的 亚基α和β β-亚基是一种特殊的β-亚基。 垂体促性腺激素细胞的限制亚基及其调节 在控制FSH产生方面至关重要。 17 β-雌二醇 (E)和孕酮（P）迅速减少FSH的分泌， 羊、猪和人的脑垂体培养物;来自羊的数据 表明E和P降低两种亚基mRNA转录 在2小时（beta）和12小时（alpha）内减少> 85%。 我们建议 定义FSH β亚基基因上的那些DNA序列， 介导E和P诱导的抑制。 这些序列可以是 类固醇受体结合位点，导致负调节 转录。 新合成的蛋白质似乎不介导 FSH抑制，因为放线菌酮不改变抑制作用。 负责负性的生物功能序列 监管将通过其赋予E-和P-的能力来定位， 在报告基因的瞬时表达过程中， 在激素敏感性人绒毛膜癌细胞系中的表达 (JAR细胞）。 这些细胞天然表达两种促性腺激素基因 与FSH β（α和hCG β）相关，它们可以被E- 通过用表达小基因的质粒转染应答 编码E受体;表达P 受体很快就会上市。 富集原代绵羊 促性腺激素细胞也将被开发作为一种可能的替代， 或与之相伴，用于研究阴性类固醇的细胞 调控 蛋白质的参与，而不是E或P 受体，在负类固醇作用将研究通过检查 细胞蛋白与E和P沉默子DNA的结合。 我们的研究 目的是为了更好地了解1）阴性基因 哺乳动物的调节（一个知之甚少的领域，部分 由于缺乏模型系统研究）和2）E的作用 和P，它们之所以重要，是因为它们在 生殖，它们明显参与转录 某些肿瘤的调节因子及其作为类固醇模型的用途 激素作用。 FSH β亚基的调节研究 也很重要，因为它们定义了控制 FSH合成/分泌，因此，性腺功能和 生育

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.