INTRAGONADOTROPE PATHWAYS REGULATING GENE TRANSCRIPTION

促性腺激素内调节基因转录的途径

• 批准号: 7425789
• 负责人: John C Marshall
• 金额: $ 18.64万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-08-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7425789
• 关键词: Amenorrhea; Biological; Calcium/calmodulin-dependent protein kinase; Cell surface; Cells; Cyclic AMP-Dependent Protein Kinases; Data; Disease; Feedback; Female; Follicle Stimulating Hormone; Follistatin; Frequencies; Gene Expression; Genes; Genetic Transcription; Goals; Gonadal Steroid Hormones; Gonadotropin Hormone Releasing Hormone; Gonadotropin-Releasing Hormone Receptor; Gonadotropins; Half-Life; Human; Hyperprolactinemia; Hypothalamic structure; Infertility; Luteinizing Hormone; MAPK14 gene; MAPK8 gene; Measures; Mediating; Methods; Numbers; Ovarian; Pathway interactions; Pattern; Peptides; Physiologic pulse; Physiological; Pituitary Gland; Play; Proteins; Pulse taking; Rattus; Regulation; Reproduction; Reverse Transcriptase Polymerase Chain Reaction; Role; Role playing therapy; Signal Transduction Pathway; Site; Specificity; Steroids; Syndrome; System; Testosterone; Time; Transcript; Woman; response

DESCRIPTION (provided by applicant): The goal of this proposal is to define the intra-gonadotrope signal transduction pathways in primary pituitary gonadtrope cells that mediate differential transcriptional responses to gonadotropin releasing hormone (GnRH) pulse frequency. Mammalian reproduction is controlled by luteinizing hormone (LH) and follicle stimulating hormone (FSH), which consist of a common alpha (a) subunit and unique beta (b) subunits that provide biological specificity. Gonadotropin subunit and other gonadotrope genes are regulated by GnRH pulse pattern, particularly pulse frequency. Gonadotrope genes are also regulated by gonadal steroids and peptides, which act in part on the pituitary to modify gene expression and responses to GnRH. Additionally, an intra-gonadotrope system, activinbB and follistatin (FS), regulates FSHB expression. We propose to use dissociated female rat pituitary cells to delineate the roles of GnRH receptor number and specific intracellular (3rd) messenger pathways (ERK, JNK, p38, PKC, Ca/CaMK II and IV, PKA) in effecting differential gonadotrope gene (a, LHb, FSHb, GnRH receptor, activinbB, FS) responses to GnRH pulse frequency. As recent data show that gonadal steroids can modulate several of these pathways, we will also assess the actions of steroids in modulating specific 3rd messenger responses to GnRH. This scientific approach will be somewhat unique, in that normal rat pituitary cells will receive physiological experimental paradigms (i.e. pulsatile GnRH) with effects on transcriptional activity assessed by quantitation of endogenous gene products (i.e. gonadotrope primary transcripts, PTs; measured by RT-PCR). Since PT half-life is relatively short (< 20 min for LHb and FSHb PTs), this method allows assessment of near 'real-time' transcriptional activity. In women, the sequential stimulation of FSH and LH is essential for cyclic ovulatory function and abnormalities in GnRH pulse pattern and gonadal steroid feedback occur in anovulatory disorders. Slow frequency pulses are present in hypothalamic amenorrhea and hyperprolactinemia. In contrast, persistently rapid GnRH pulse frequency is a feature of polycystic ovarian syndrome (PCOS). Recent data show that elevated testosterone disrupts normal hypothalamic-pituitary regulation of gonadotrope function and appears to play a role in the genesis of PCOS. Thus, understanding the mechanisms of GnRH and steroid actions at the gonadotrope are essential to evolving effective methods to restore normal LH and FSH expression/secretion and treating human infertility.

描述（由申请人提供）：本提案的目标是定义初级垂体促性腺细胞中的促性腺激素内信号转导途径，该途径介导对促性腺激素释放激素（GnRH）脉冲频率的差异转录反应。哺乳动物的繁殖由黄体生成素 (LH) 和卵泡刺激素 (FSH) 控制，它们由常见的 α (a) 亚基和提供生物特异性的独特 β (b) 亚基组成。促性腺激素亚基和其他促性腺激素基因受 GnRH 脉冲模式（特别是脉冲频率）调节。促性腺激素基因也受到性腺类固醇和肽的调节，它们部分作用于垂体以改变基因表达和对 GnRH 的反应。此外，促性腺内系统、activinbB 和卵泡抑素 (FS) 调节 FSHB 表达。我们建议使用分离的雌性大鼠垂体细胞来描述 GnRH 受体数量和特定细胞内（第三）信使途径（ERK、JNK、p38、PKC、Ca/CaMK II 和 IV、PKA）在影响不同促性腺激素基因（a、LHb、FSHb、GnRH 受体、activinbB、FS）反应中的作用。 GnRH 脉冲频率。最近的数据表明，性腺类固醇可以调节其中的几种途径，我们还将评估类固醇在调节 GnRH 特定第三信使反应中的作用。这种科学方法有些独特，因为正常大鼠垂体细胞将接受生理实验范式（即脉冲 GnRH），通过内源基因产物（即促性腺激素初级转录本，PT；通过 RT-PCR 测量）的定量来评估对转录活性的影响。由于 PT 半衰期相对较短（LHb 和 FSHb PT 小于 20 分钟），因此该方法可以评估近乎“实时”的转录活性。 在女性中，FSH 和 LH 的连续刺激对于周期性排卵功能至关重要，并且在无排卵疾病中会出现 GnRH 脉冲模式和性腺类固醇反馈异常。慢频率脉冲出现在下丘脑闭经和高催乳素血症中。相反，持续快速的 GnRH 脉冲频率是多囊卵巢综合征 (PCOS) 的一个特征。最近的数据表明，睾酮升高会扰乱下丘脑-垂体对促性腺激素功能的正常调节，并且似乎在多囊卵巢综合征的发生中发挥作用。因此，了解 GnRH 和类固醇对促性腺激素的作用机制对于开发恢复正常 LH 和 FSH 表达/分泌以及治疗人类不育症的有效方法至关重要。