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Neurosecretory Gene Expression in the Hypothalamus

下丘脑的神经分泌基因表达

基本信息

批准号：
10619540
负责人：
PAMELA L MELLON
金额：
$ 54.05万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-15 至 2025-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10619540
关键词：
Address Adult Anterior Apoptosis Argipressin Axon Cell Differentiation process Cell Line Cells Circadian Rhythms Cues Defect Development Embryo Estrous Cycle Exhibits Failure Feeds Fertility Foundations Gene Expression Gene Expression Regulation Genes Genetic Genetic Transcription Goals Gonadal Steroid Hormones Gonadotropin Hormone Releasing Hormone Heterozygote Homeobox Homeodomain Proteins Hormones Hypothalamic structure In Vitro Infertility KISS1 gene Knock-out Knockout Mice Laboratories Methodology Molecular Morphology Mus Mutation Neurites Neuroendocrine Cell Neurons Neuropeptides Neurosecretory Systems Olfactory Nerve Pathway interactions Perinatal mortality demographics Physiological Pituitary Gland Population Puberty Regulation Regulatory Pathway Reproduction Role Sex Behavior Signal Transduction Small Interfering RNA Testosterone Transfection Transgenic Organisms VIP gene Vasoactive Intestinal Peptide Ventral Anterior Thalamic Nucleus circadian circadian pacemaker experience homeodomain in vitro Model in vivo innovation insight male median eminence migration neural circuit neuron development neuronal circuitry novel promoter reproductive reproductive function response subfertility suprachiasmatic nucleus transcription factor

项目摘要

Project Summary The neural circuit that controls mammalian reproduction delivers circadian information from the suprachiasmatic nucleus (SCN) via the neuropeptides arginine vasopressin (AVP) and vasoactive intestinal peptide (VIP) to the kisspeptin (Kiss) and gonadotropin-releasing hormone (GnRH) neurons, respectively. Infertility can be caused at the neuroendocrine level by genetic defects in GnRH neurons, Kiss neurons, and/or circadian pacemaker and neuropeptide neurons in the SCN. GnRH neurons arise in the olfactory placode, migrate into the hypothalamus, and extend their axons to the median eminence to deliver GnRH to the pituitary in response to Kiss signals. Disrupted migration, neurite pathfinding, and/or disregulated secretion of Kiss or GnRH neurons result in failures of puberty, fertility, and reproductive function. We have determined that the homeodomain transcription factors, Vax1, Six3, and Six6, are all crucial for reproduction. Six6 Knock-out (KO) mice exhibit strikingly decreased fertility, while heterozygote Vax1 and Six3 mice are subfertile (Vax1 and Six3 KO mice are perinatal lethal). Though GnRH neuron numbers are normal at e13.5, all three of the KO embryos have ~90% reductions in hypothalamic GnRH neurons by e17.5. Vax1, Six3, and Six6 are found in Kiss neurons and regulate expression of the Kiss promoter in Kiss-expressing cell lines. In addition, deletion of Six3 from Kiss neurons causes subfertility. Furthermore, all three KO e17.5 embryos lack SCN morphology and fail to express AVP and VIP, and Six6 KO adults lack circadian rhythms. The overall goal of this application is to elucidate the development of this fundamental reproductive neuroendocrine circuit (SCNKissGnRH) at the molecular, developmental, and physiological levels. We propose three Specific Aims: Aim 1 will investigate differentiation and maturation of GnRH neurons during migration by determining the fate of neurons lacking these factors and effects on their migratory pathway. Aim 2 will focus on the roles of Vax1, Six3, and Six6 in the development and function of Kiss neurons in vitro and in vivo with a focus on direct regulation of Kiss gene expression and effects on fertility. Aim 3 will address the fundamental mechanisms of SCN development, the contribution of Vax1, Six3, and Six6 to AVP and VIP gene expression, and investigate the roles of SCN circadian function in fertility. Our overarching hypothesis is that infertility due to defects in Vax1, Six3, and Six6 is caused by alterations in specific hypothalamic neuroendocrine cell populations within the hypothalamic SCNKissGnRH reproductive neurocircuit by regulation of development, hormone synthesis, and circadian rhythms. We believe that studies of these key homeodomain proteins will reveal fundamental mechanisms in the control of reproductive function and circadian rhythms and provide valuable insight into novel regulatory pathways important for the development and function of this neuroendocrine circuit. This multifaceted approach will yield a comprehensive understanding of their roles in fertility and circadian rhythms in vivo and in vitro, and provide further insight into the fundamental genetic control of infertility and circadian rhythms.

项目概要控制哺乳动物繁殖的神经回路从视交叉上传递昼夜节律信息细胞核（SCN）通过神经肽精氨酸加压素（AVP）和血管活性肠肽（VIP）到达分别是 Kisspeptin (Kiss) 和促性腺激素释放激素 (GnRH) 神经元。可能会导致不孕不育在神经内分泌水平上，GnRH 神经元、Kiss 神经元和/或昼夜节律起搏器的遗传缺陷导致 SCN 中的神经肽神经元。 GnRH 神经元出现在嗅板，迁移到下丘脑，并将它们的轴突延伸到正中隆起，以响应 Kiss 信号将 GnRH 传递到垂体。迁移中断、神经突寻路和/或 Kiss 或 GnRH 神经元分泌失调会导致失败青春期、生育力和生殖功能。我们已经确定同源域转录因子， Vax1、Six3 和 Six6 对于繁殖都至关重要。 Six6 基因敲除 (KO) 小鼠表现出显着下降生育能力，而杂合子 Vax1 和 Six3 小鼠生育力低下（Vax1 和 Six3 KO 小鼠围产期致死）。尽管 GnRH 神经元数量在 e13.5 时正常，但所有三个 KO 胚胎的 GnRH 神经元数量均减少了约 90% e17.5 的下丘脑 GnRH 神经元。 Vax1、Six3 和 Six6 存在于 Kiss 神经元中并调节表达 Kiss表达细胞系中Kiss启动子的作用。此外，从 Kiss 神经元中删除 Six3 会导致生育能力低下。此外，所有三个 KO e17.5 胚胎都缺乏 SCN 形态并且无法表达 AVP 和 VIP， Six6 KO 成虫缺乏昼夜节律。该应用程序的总体目标是阐明开发这个基本的生殖神经内分泌回路（SCNKissGnRH）在分子、发育、和生理水平。我们提出三个具体目标：目标 1 将研究分化和成熟通过确定缺乏这些因子的神经元的命运及其对其的影响，对迁移过程中的 GnRH 神经元进行研究迁徙途径。 Aim 2 将重点关注 Vax1、Six3 和 Six6 在 Kiss 的开发和功能中的作用体外和体内神经元的研究，重点是 Kiss 基因表达的直接调节及其对生育力的影响。目的 3 将讨论 SCN 发育的基本机制，Vax1、Six3 和 Six6 对 SCN 发育的贡献 AVP 和 VIP 基因表达，并研究 SCN 昼夜节律功能在生育力中的作用。我们的首要任务假设 Vax1、Six3 和 Six6 缺陷导致的不孕症是由特定基因的改变引起的下丘脑 SCN 内的下丘脑神经内分泌细胞群KissGnRH 生殖通过调节发育、激素合成和昼夜节律来调节神经回路。我们相信，研究这些关键同源域蛋白的研究将揭示控制生殖功能的基本机制和昼夜节律，并为对发展重要的新监管途径提供宝贵的见解以及该神经内分泌回路的功能。这种多方面的方法将产生全面的理解它们在体内和体外的生育和昼夜节律中的作用，并提供对基本原理的进一步见解不孕症和昼夜节律的遗传控制。