Sex Steroids, Kisspeptin and Regulation of GnRH

性类固醇、Kisspeptin 和 GnRH 的调节

基本信息

批准号：
10378039
负责人：
Jon E Levine
金额：
$ 46.52万
依托单位：
RBHS-ROBERT WOOD JOHNSON MEDICAL SCHOOL
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：
2020-06-01 至 2023-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10378039
关键词：
Acceleration Adult Adult Children Alleles Animal Model Animals Axon Blood Vessels Brain Cell Nucleus Cells Defect Delayed Puberty Development Doxycycline Dynorphins ESR1 gene ESR2 gene Elements Enterobacteria phage P1 Cre recombinase Estradiol Estrogen Receptor alpha Feedback Female Fertility Fertility Disorders Follicle Stimulating Hormone Gene Deletion Generations Genetic Genetic Recombination Gonadal Steroid Hormones Gonadotropin Hormone Releasing Hormone Gonadotropins Hormone secretion Hypothalamic structure Impairment Infertility Internal Ribosome Entry Site Intervention KISS1 gene Knock-out Laboratories Light Luteinizing Hormone Mediating Methodology Modeling Mus Neuraxis Neurokinin B Neurons Neuropeptides Neurosecretion Neurosecretory Systems Partner in relationship Pattern Peptides Periodicity Phenotype Physiologic pulse Play Polycystic Ovary Syndrome Population Precocious Puberty Process Puberty Regulation Role Steroid Receptors Steroids Structure of nucleus infundibularis hypothalami Synapses System TACR3 gene Testing autocrine base dynorphin receptor functional hypothalamic amenorrhea gonad function innovation kappa opioid receptors knockout gene male mature animal median eminence mouse model neuromechanism novel paracrine preoptic nucleus prodynorphin receptor receptor binding reproductive reproductive axis reproductive function reproductive system disorder tool

项目摘要

Project Summary The central nervous system regulates gonadotropin secretion through neurosecretion of gonadotropin- releasing hormone (GnRH). GnRH is synthesized in preoptic and periventricular neurons, transported via intertwined processes that distribute as axonal-vascular terminals in the median eminence and released into the hypothalamic-hypophysial portal vasculature. GnRH binds receptors on gonadotropes to stimulate secretion and synthesis of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Neurosecretion of GnRH is pulsatile and is obligatory for sustaining normal gonadotropin secretion and synthesis. Kisspeptin (KISS1) neurons are a major GnRH afferent network that activates GnRH neurons during puberty, maintains GnRH release during adulthood, and transduces negative and positive feedback actions of gonadal steroids. In our studies we will test the hypothesis that KISS1 neurons, specifically those in the arcuate nucleus (ARC) that co-express the peptides neurokinin B (NKB) and prodynorphin (PDyn) (KNDy neurons), function as a GnRH pulse generator (Aim 1), with NKB mediating synchronized activation of KNDy cells (Aim 2) and dynorphin terminating each pulse discharge (Aim 3). These studies are significant because they will provide information on the cellular circuitries that govern GnRH pulse generation, and thus will shed new light on the pathophysiologic mechanisms underlying neuroendocrine-based fertility disorders, such as absent, delayed, or precocious puberty, functional hypothalamic amenorrhea, or polycystic ovary syndrome, and in the longer term, point to new potential targets for intervention in these reproductive impairments. The proposed studies will use powerful genetic tools to dissect and characterize the functional components of the kisspeptin-GnRH pulse generating system. To define the key elements of the pulse generator, we will utilize innovative genetically modified mouse models, each enabling an analysis of the consequences of kisspeptin neuron-specific gene deletion. We will first study the role of the KNDy neuronal population using a Kiss1fl/fl mouse recently created in our laboratory. This mouse will be bred to a prodynorphin Cre (Pdyn-IRES- Cre21,2) mouse, hereafter Pdyn-Cre, to eliminate Kiss1 in KNDy neurons. We have also developed a novel mouse bearing a doxycycline-inducible kisspeptin-Cre allele (iKiss-Cre mouse) that will enable temporal control over the selective deletion of genes from Kiss1 neurons. Two other lines, a NKBfl/fl mouse (developed in our laboratory) and an Oprk1fl/fl mouse (Jackson labs) will be crossed to Kiss1-Cre or iKiss-Cre mice to generate mice that will allow us to analyze the effects of kisspeptin neuron-specific deletion of NKB and Oprk1 on GnRH- triggered LH pulses. We will also use the iKiss-Cre mouse to delete and study the roles of steroid receptors in kisspeptin neurons in the adult. This temporally controlled gene deletion will eliminate a longstanding technical limitation of conventional steroid receptor knockout models in which steroid regulation of the axis is confounded by steroid developmental and organizational effects in the axis.

项目概要中枢神经系统通过促性腺激素的神经分泌来调节促性腺激素的分泌释放激素（GnRH）。 GnRH 在视前神经元和室周神经元中合成，通过交织在一起的过程，作为轴突血管末端分布在正中隆起并释放到下丘脑-垂体门脉系统。 GnRH 与促性腺激素受体结合以刺激分泌和黄体生成素（LH）和卵泡刺激素（FSH）的合成。 GnRH 的神经分泌是脉动并且对于维持正常的促性腺激素分泌和合成是必需的。 Kisspeptin (KISS1) 神经元是一个主要的 GnRH 传入网络，在青春期，维持成年期 GnRH 释放，并转导负反馈和正反馈作用性腺类固醇。在我们的研究中，我们将检验 KISS1 神经元（特别是弓形神经元）的假设共表达肽神经激肽 B (NKB) 和前强啡肽 (PDyn) 的细胞核 (ARC)（KNDy 神经元），作为 GnRH 脉冲发生器（目标 1），NKB 介导 KNDy 细胞的同步激活（目标 2）和强啡肽终止每次脉冲放电（目标 3）。这些研究意义重大，因为它们将提供有关控制 GnRH 脉冲生成的细胞电路的信息，因此将为研究基于神经内分泌的生育障碍的病理生理机制，例如缺失、延迟或性早熟、功能性下丘脑闭经或多囊卵巢综合征，从长远来看，指出了干预这些生殖障碍的新的潜在目标。拟议的研究将使用强大的遗传工具来剖析和表征功能 Kisspeptin-GnRH 脉冲发生系统的组成部分。要定义脉冲发生器的关键元件，我们将利用创新的转基因小鼠模型，每个模型都能够分析 Kisspeptin 神经元特异性基因缺失。我们将首先使用 KNDy 神经元群的作用来研究 Kiss1fl/fl 鼠标是我们实验室最近创建的。这只小鼠将被培育成强啡肽原 Cre (Pdyn-IRES- Cre21,2) 小鼠，以下简称 Pdyn-Cre，用于消除 KNDy 神经元中的 Kiss1。我们还开发了小说携带多西环素诱导的 Kisspeptin-Cre 等位基因的小鼠（iKiss-Cre 小鼠），可实现时间控制选择性删除 Kiss1 神经元的基因。另外两个品系，NKBfl/fl 小鼠（在我们的实验室）和 Oprk1fl/fl 小鼠（杰克逊实验室）将与 Kiss1-Cre 或 iKiss-Cre 小鼠杂交以生成小鼠，这将使我们能够分析 Kisspeptin 神经元特异性删除 NKB 和 Oprk1 对 GnRH 的影响触发 LH 脉冲。我们还将使用 iKiss-Cre 小鼠删除并研究类固醇受体在成人的 Kisspeptin 神经元。这种暂时控制的基因删除将消除长期存在的技术传统类固醇受体敲除模型的局限性，其中类固醇对轴的调节是混乱的通过类固醇对轴的发育和组织影响。