Neurosecretory Gene Expression in the Hypothalamus

下丘脑的神经分泌基因表达

• 批准号: 8687984
• 负责人: PAMELA L MELLON
• 金额: $ 31.26万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-01-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8687984
• 关键词: Address; Anterior; Apoptosis; Area; Axon; Binding; Biological Models; Biology; CCAAT-Enhancer-Binding Proteins; Cell Differentiation process; Cells; Complex; Cues; DNA; Development; Enhancers; Epigenetic Process; Failure; Fertility; Foundations; Functional RNA; Gene Expression; Genes; Genetic; Goals; Gonadotropin Hormone Releasing Hormone; Gonadotropins; Grant; Histone H3; Homeobox; Homeodomain Proteins; Human; Hypothalamic Hormones; Hypothalamic structure; In Situ Hybridization; In Vitro; Infertility; Kallmann Syndrome; Klinefelter' s Syndrome; Knockout Mice; Mediating; Menopause; Methodology; Mining; Modeling; Molecular; Mus; Mutation; NF1 gene; Neurons; Nucleic Acid Regulatory Sequences; Pathway interactions; Patients; Periodicity; Polycomb; Polymerase; Population; Prader-Willi Syndrome; Puberty; RNA; Regulation; Regulatory Element; Repression; Reverse Transcriptase Polymerase Chain Reaction; Role; Sequence Analysis; Specific qualifier value; Specificity; Structure; Testing; Transcriptional Regulation; Untranslated RNA; cell motility; cribriform plate; homeodomain; hypothalamic pituitary gonadal axis; in vivo; innovation; insight; median eminence; migration; mouse model; necdin; novel; olfactory bulb; programs; promoter; reproductive function; transcription factor; vomeronasal organ

DESCRIPTION (provided by applicant): Gonadotropin-releasing hormone (GnRH) drives the hypothalamic-pituitary-gonadal axis. The GnRH neurons have an extraordinary origin. In the mouse, they arise in the presumptive vomeronasal organ within the olfactory placode at e11.5. As they differentiate, they migrate past the cribriform plate, through the olfactory bulb and into the hypothalamus, finally extending their axons to the median eminence. This discrete population of ~800 neurons, scattered through the hypothalamus, controls puberty, menstrual cyclicity, fertility, and meno- pause. Disrupted migration or disregulated secretion results in failures in puberty, fertility, and reproductive function. The overall goal of this renewal application is to elucidate the molecular, epigenetic, and developmental mechanisms that regulate hypothalamic GnRH neuron migration and maturation. We will utilize two major model systems: our immortalized GnRH-secreting hypothalamic cells (GT1) and genetically modified mice. Under the support of this long-standing grant, we have identified evolutionarily conserved promoter and enhancer regions that target GnRH gene expression exclusively to cultured GT1 cells in vitro and to GnRH neurons in vivo. We have shown that these GnRH regulatory regions are controlled by transcriptional regulators: Oct1, NF1, Gata4, Otx2, Pbx, Prep, Meis, Dlx, Msx, necdin, C/EBP¿, Six6/3, and the TLE (Grg) co- repressors, and that mouse models lacking any one of a number of these fail to produce the correct population of GnRH neurons and/or disrupt migration in vivo. For this renewal application, we propose three novel aims: Aim 1 will address the differentiation and maturation of the GnRH neuron during migration determining the fate of neurons that lack expression of factors in the Dlx/Msx/Necdin pathway, and elucidate the mechanism of Msx repression of GnRH gene expression. Aim 2 will focus on specific homeodomain factors crucial for the development of the hypothalamus as a whole and determine their role in GnRH neuron migration and maturation in vivo and in vitro. Aim 3 will address the fundamental mechanisms of the neuron-specific enhancers of the GnRH gene. We have discovered that the major enhancer critical for neuron-specific GnRH expression is bound by activated Polymerase II and is transcribed into RNA. This long, noncoding RNA will be characterized in vitro and in vivo and its mechanisms of action will be determined. The homologous enhancers in human will be analyzed and screened for mutations in hypogonadal patient DNA. Our overarching hypothesis is that developmental migration and maturation of the GnRH neuron require the acquisition of a transcriptional regulatory program that relies on developmental coordination of homeodomain transcription factors and long non-coding enhancer RNA. We believe these studies will provide valuable insight into novel regulatory mechanisms and enable progression beyond the currently accepted paradigms. This multifaceted approach should yield a comprehensive understanding of the program of GnRH neuronal migration and cell fate in vivo and in vitro and provide insight into the genetics of hypogonadotropic hypogonadism.

描述（由适用提供）：促性腺激素释放的马龙（GNRH）驱动下丘脑 - 垂体 - 轴轴。 GNRH神经元具有非凡的起源。在鼠标中，它们在E11.5的嗅觉placode内的假定选民器官中产生。当它们区分时，它们通过嗅球迁移到丝布状板上并进入下丘脑，最终将其轴突扩展到中位数。通过下丘脑散布的〜800个神经元的离散人群，控制着青春期，月经循环，生育能力和蒙斯诺（Menno-Pause）。破坏的迁移或无调分泌导致青春期，生育和生殖功能失败。这种更新应用的总体目标是阐明调节下丘脑GNRH神经元迁移和成熟的分子，表观遗传和发育机制。我们将利用两个主要的模型系统：我们的永生化下丘脑细胞（GT1）和转基因小鼠。在这个长期以来的赠款的支持下，我们已经确定了进化构成的启动子和增强子区域，这些启动子和增强子区域将GnRH基因表达仅针对培养的GT1细胞在体外和体内的GNRH神经元中。我们已经表明，这些GNRH调节区域由转录调节器控制：OCT1，NF1，GATA4，OTX2，OTX2，PBX，PREP，PREP，MEIS，MEIS，DLX，MSX，NECDIN，NECDIN，NECDIN，c/eBPTH，SIX6/3和TLE（GRG）的同事（GRG）均缺乏这些数字，这些人缺乏这些数字，这些人数均缺乏这些数字，这些数字是一部分的数字。和/或在体内中断迁移。 For this renewal application, we propose three novel aims: Aim 1 will address the differentiation and maturation of the GnRH neuron during migration determining the fate of neurons that lack expression of factors in the Dlx/Msx/Necdin pathway, and elucidate the mechanism of Msx Aim 2 will focus on specific homeodomain factors crucial for the development of the hypothalamus as a whole and determine their role in GnRH neuron体内和体外的迁移和成熟。 AIM 3将解决GNRH基因神经特异性增强子的基本机制。我们已经发现，神经元特异性GNRH表达至关重要的主要增强子由活化的聚合酶II结合，并转录为RNA。将在体外表征这种长而无编码的RNA，并将确定体内及其作用机理。将分析和筛选人类中的同源增强子，以获取性质性心脏病患者DNA中的突变。我们的总体假设是，GNRH神经元的发育迁移和成熟需要获得转录调节计划，该计划依赖于副域转录因子的发展协调和长期非编码增强子RNA。我们认为，这些研究将为新的监管机制提供宝贵的见解，并使在当前公认的范式之外的发展。这种多方面的方法应该对体内和体外细胞命运和细胞命运和体外的细胞命运程序有全面的了解，并提供对性肾上腺素性性降低性降低症的遗传学的见解。