INTRAGONADOTROPE PATHWAYS REGULATING GENE TRANSCRIPTION

促性腺激素内调节基因转录的途径

• 批准号: 7247899
• 负责人: John C Marshall
• 金额: $ 19.02万
• 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/7247899
• 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）：本提案的目的是确定原发性垂体促性腺细胞中介导促性腺激素释放激素（GnRH）脉冲频率差异转录反应的促性腺激素内信号转导通路。哺乳动物的生殖是由促黄体生成素（LH）和促卵泡激素（FSH）控制的，它们由共同的α (a)亚基和独特的β (b)亚基组成，提供生物学特异性。促性腺激素亚基和其他促性腺激素基因受GnRH脉冲模式，特别是脉冲频率的调节。促性腺激素基因也受性腺激素和肽的调节，它们部分作用于垂体，以改变基因表达和对GnRH的反应。此外，促性腺激素系统，激活bb和卵泡抑素（FS），调节FSHB的表达。我们建议使用分离的雌性大鼠垂体细胞来描述GnRH受体数量和特定的细胞内(3)信使通路（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）对GnRH脉冲频率的反应中的作用。由于最近的数据显示，性腺类固醇可以调节这些途径中的几种，我们还将评估类固醇在调节GnRH特异性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（即脉动GnRH），并通过内源性基因产物（即促性腺激素初级转录本，PTs；通过RT-PCR测量）的定量评估对转录活性的影响。由于PT的半衰期相对较短（LHb和FSHb PT的半衰期< 20分钟），因此该方法可以评估近乎“实时”的转录活性。