CREB and ICER, the Yin and Yang of FSH-beta regulation by pulsatile GnRH

CREB ​​和 ICER，脉动 GnRH 调节 FSH-β 的阴阳

• 批准号: 8791474
• 负责人: Iain Thompson
• 金额: $ 13.63万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-11 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8791474
• 关键词: Address; Affect; Affinity; Amenorrhea; Anterior Pituitary Gland; Automobile Driving; Award; Binding; CREB1 gene; Cardiovascular Abnormalities; Cell Line; Cell surface; Cells; Coupled; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Cyclic AMP-Responsive DNA-Binding Protein; Disease; Equilibrium; Ethics; Event; Fellowship; Female; Fertility; Frequencies; Gametogenesis; Genes; Genetic Transcription; Goals; Gonadotropin Hormone Releasing Hormone; Gonadotropins; Hormones; Hospitals; Hypothalamic Dysfunction Syndromes; Hypothalamic structure; In Vitro; Infertility; Insulin Resistance; Kallmann Syndrome; Knock-out; Lead; Leadership; Link; Mediating; Metabolic; Modeling; Molecular; Mus; Neurons; Neuropeptides; Neurosecretory Systems; Obesity; Ovarian; Ovary; Pathway interactions; Patients; Pattern; Periodicity; Phosphorylation; Physiologic pulse; Physiological; Pituitary Gland; Population; Positioning Attribute; Postdoctoral Fellow; Production; Protein Binding; Protein Dephosphorylation; Protein phosphatase; Regulation; Repressor Proteins; Reproduction; Research; Research Personnel; Signal Transduction; Site; Steroid biosynthesis; Syndrome; System; Testis; Training Programs; Transcription Factor AP-1; Ubiquitin; Woman; Yin-Yang; age group; base; beta Subunit Follicle Stimulating Hormone; in vivo; insight; interest; male; meetings; mouse model; multicatalytic endopeptidase complex; new therapeutic target; novel therapeutic intervention; promoter; public health relevance; receptor; reproductive; reproductive function; response; transcription factor

DESCRIPTION (provided by applicant): During my post-doctoral fellowship, I have continued my interest in the neuroendocrine control of reproduction and the mechanism by which the gonadotrope decodes the pulsatile GnRH signal, released from GnRH neurons in the hypothalamus. This award will provide the opportunity to meet my long-term goal of becoming an independent investigator, supplementing the leadership, research, and ethical training programs offered by Brigham and Women's Hospital. Production of pituitary FSH and LH, under the control of pulsatile GnRH, is essential for fertility. Pituitary FSHß-subunit (FSHß) transcription and hence FSH secretion are preferentially stimulated at slow rather than fast frequencies of pulsatile GnRH, in contrast to LHß. The mechanisms for this disparity are not known. The goal of this project is to elucidate the underlying mechanisms that contribute to the GnRH pulse frequency-dependent differential control of FSHß transcription and subsequent FSH synthesis. Using our perifusion system and the murine gonadotrope-derived LßT2 cell line model, we have shown previously that GnRH activation of CREB mediates preferential induction of FSHß at slower GnRH pulse frequencies, whereas ICER is induced at high GnRH pulse frequencies and antagonizes the stimulatory effects of CREB. The molecular mechanisms by which pulsatile GnRH regulates CREB and ICER expression, activation, and regulation remain poorly understood. I propose to extend our prior in vitro observations in cell lines to in vivo mouse models, and predict that gonadotrope-specific CREB and ICER deficient mouse models will further demonstrate the critical function of these transcription factors in decoding oscillatoy GnRH signals from the hypothalamus, by demonstrating disrupted cyclicity and impaired reproductive function. The specific objectives are to determine the manner in which two transcription factors, cAMP response element binding protein (CREB) and inducible cAMP early repressor (ICER), mediate the differential response of FSHß to pulsatile GnRH in the gonadotrope to contribute to reproductive function. To achieve these objectives, the following aims are proposed: 1) Investigate the mechanisms by which PKA activity and CREB phosphorylation status are regulated by pulsatile GnRH to preferentially stimulate FSHß transcription at slow versus fast frequencies; 2) Investigate the pathways that regulate ICER synthesis, action and degradation in a GnRH pulse frequency-dependent manner; 3) Study the effect of CREB and ICER gene disruption in gonadotropes on FSHß transcription and reproductive function in vivo. The elucidation of the mechanisms by which FSHß transcription is regulated by pulsatile GnRH could provide novel therapeutic targets for reproductive disorders such as polycystic ovarian syndrome (PCOS) and hypothalamic amenorrhea (HA).

描述（由申请人提供）：在博士后期间，我继续对生殖的神经内分泌控制和促性腺激素解码下丘脑GnRH神经元释放的脉动性GnRH信号的机制感兴趣。这个奖项将为我提供机会，实现我成为一名独立研究者的长期目标，补充布莱根妇女医院提供的领导力、研究和道德培训项目。在脉动性GnRH的控制下，垂体FSH和LH的产生对生育至关重要。与LHß相反，垂体FSHß-亚单位（FSHß）转录和FSH分泌在脉动GnRH的慢频率而不是快频率下优先受到刺激。造成这种差异的机制尚不清楚。该项目的目标是阐明GnRH脉冲频率依赖性FSHß转录和随后的FSH合成的差异控制的潜在机制。利用我们的灌注系统和小鼠促性腺激素衍生的LßT2细胞系模型，我们之前已经证明，GnRH激活CREB在较慢的GnRH脉冲频率下介导FSHß的优先诱导，而ICER在高GnRH脉冲频率下诱导，并拮抗CREB的刺激作用。脉动性GnRH调控CREB和ICER表达、激活和调控的分子机制尚不清楚。我建议将我们之前在细胞系中的体外观察扩展到体内小鼠模型，并预测促性腺激素特异性CREB和ICER缺陷小鼠模型将进一步证明这些转录因子在解码来自下丘脑的振荡GnRH信号中的关键功能，通过证明周期被破坏和生殖功能受损。具体目的是确定两种转录因子cAMP反应元件结合蛋白（CREB）和诱导型cAMP早期抑制因子（ICER）介导促性腺激素中FSHß对脉动GnRH的差异反应，从而促进生殖功能的方式。为了实现这些目标，我们提出了以下目标：1)研究脉冲GnRH调节PKA活性和CREB磷酸化状态的机制，以优先刺激FSHß在慢频率和快频率下的转录；2)以GnRH脉冲频率依赖的方式研究调节ICER合成、作用和降解的途径；3)研究促性腺激素中CREB和ICER基因破坏对体内FSHß转录和生殖功能的影响。阐明搏动性GnRH调控FSHß转录的机制可以为多囊卵巢综合征（PCOS）和下丘脑闭经（HA）等生殖疾病的治疗提供新的靶点。