Neuropeptide regulation of neurohypophyseal function

神经肽调节神经垂体功能

基本信息

批准号：
7748924
负责人：
FRANCIS W FLYNN
金额：
$ 27.31万
依托单位：
UNIVERSITY OF WYOMING
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-02-01 至 2012-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7748924
关键词：
Actins Address Affect Agonist Amino Acid Sequence Antibodies Antihypertensive Agents Behavioral Binding Blood Brain Cell Nucleolus Cell Nucleus Cell membrane Co-Immunoprecipitations Confocal Microscopy Congestive Heart Failure Cytoplasm DNA Binding Data Detection Epilepsy Excretory function Functional disorder Gene Expression Regulation Genetic Transcription Genomics Goals Hormones Human Human Pathology Hydralazine Hypertension Hypotension Hypothalamic structure Hypovolemia Immunoelectron Microscopy Immunoprecipitation Ingestion Injection of therapeutic agent Intraventricular Injections Laboratories Ligands Link Maintenance Membrane Messenger RNA Minor Neurokinin B Neuromedin K Receptor Neurons Neuropeptides Neurosecretory Systems Neurotransmitters Nuclear Nuclear Translocation Osmolar Concentration Oxytocin Pathology Physiological Plasma Play Posterior Pituitary Hormones Preparation Principal Investigator Protein translocation Proteins Publications Rattus Receptor Activation Receptor Signaling Recruitment Activity Regulation Reporting Research Role Saline Series Signal Pathway Signal Transduction Sincalide Small Interfering RNA Sodium Source Stimulus System Tachykinin Testing Thirst Time Tissues Transcriptional Regulation Vasopressins Water Western Blotting chromatin immunoprecipitation immunoreactivity in vivo insight magnocellular neurochemistry neuronal cell body novel paraventricular nucleus programs protein protein interaction public health relevance receptor receptor binding receptor coupling relating to nervous system research study response restoration supraoptic nucleus transcription factor transmission process treatment strategy

项目摘要

DESCRIPTION (provided by applicant): Bodily osmolarity is maintained in a narrow physiological range through the release of vasopressin (VP) and oxytocin (OT) into the blood where the hormones act to promote water retention and sodium excretion. The tachykinin, neurokinin B (NKB) and its NK3 receptor (NK3R) have a very unique relationship to VP because NKB and NK3R are co expressed by a majority of magnocellular VP neurons. Magnocellular NK3R are activated in response to physiological challenges because pretreatment with NK3R antagonists block both VP and OT release to both hyperosmolarity and hypovolemia/hypotension. Furthermore, NK3R play a traditional role in cellular signaling and immediate responses to hyperosmolarity and hypovolemia/hypotension and a more sustained role in regulating magnocellular neurons function through direct actions on gene transcription. Following a hyperosmotic challenge NK3R expressed by VP magnocellular neurons were shown to be translocated from the cell membrane to the cell nucleus by confocal microscopy, immuno-electron microscopy and Western blot. Nuclear NK3R was not detected under basal conditions. The translocation of activated g-protein coupled receptors into the nucleus has been hypothesized as a new paradigm for transcriptional regulation. Yet, in spite of the novelty and nuclear signaling importance of NK3R, we know little about NK3R signaling by magnocellular PVN neurons. The goals of this proposal are to identify the role of endogenous NKB and NK3R activation in magnocellular neuron function. Aim 1 will test the hypothesis that NK3R signaling is a "common path" for the activation of magnocellular neurons in the PVN in response to hyperosmotic and hypotensive challenges. Aim 2 will determine the time course of NK3R nuclear translocation and determine if NKB is translocated to the cell nucleus. The experimental hypothesis is that nuclear NK3R affects gene transcription through protein-protein interactions or by binding DNA. Co-immunoprecipitation and chromatin immunoprecipitation will be used to identify the nuclear targets of nuclear NK3R. Aim 3 will examine the effects of sustained hyperosmolarity on the regulation of NK3R and NKB mRNA in the PVN. Aim 4 will identify the source of release of the NK3R ligand (NKB). Results will identify NKB soma that are intrinsic to the PVN or that project to magnocellular PVN neurons and that are activated by hyperosmolarity. Collectively, the results will provide novel insights into membrane-bound receptors acting as nuclear transcription factors and the neurotransmitter systems controlling magnocellular neuron function. Dysfunction of VP release contributes to human pathophysiology, such as congestive heart failure, and the results may suggest novel treatment strategies and/or new insights into genomic underpinnings of human pathologies associated with NK3R system. PUBLIC HEALTH RELEVANCE The proposed research has the potential to contribute to therapies to deal with the dysregulation of neuroendocrine hormones that contribute to pathologies such as congestive heart failure and hypertension. The nuclear translocation of the neurokinin receptor to the nucleus is novel and has implications for a large number of pathologies, such as epilepsy, that are linked to this receptor system in the brain.

描述（由申请人提供）：通过释放加压素（VP）和催产素（OT），将身体渗透压保持在狭窄的生理范围内，其中激素可以促进水保留水和钠排泄物。旋转金蛋白，神经蛋白B（NKB）及其NK3受体（NK3R）与VP具有非常独特的关系，因为NKB和NK3R由大多数巨细胞VP神经元表达。大细胞NK3R因生理挑战而被激活，因为使用NK3R拮抗剂预处理，VP和OT释放都释放到高渗透和低血容量/低血压/低血压。此外，NK3R在细胞信号传导中起着传统的作用，并且对高渗透性和低血容量/低血压的直接反应以及通过直接对基因转录的直接作用来调节巨细胞神经元在调节大量细胞神经元中的作用更加持续。在通过VP巨细胞神经元表达的高渗挑战后NK3R被证明通过共聚焦显微镜，免疫电子显微镜和蛋白质印迹将细胞膜转移到细胞核。在基础条件下未检测到核NK3R。活化的G蛋白偶联受体转移到细胞核中已被认为是转录调节的新范式。然而，尽管NK3R具有新颖性和核信号的重要性，但我们对Magnocular PVN神经元的NK3R信号传导知之甚少。该提案的目标是确定内源性NKB和NK3R激活在大细胞神经元功能中的作用。 AIM 1将检验以下假设：NK3R信号传导是响应于高渗和降压和降压挑战的PVN激活PVN中巨细胞神经元的“常见路径”。 AIM 2将确定NK3R核转运的时间过程，并确定NKB是否转移到细胞核。实验假设是核NK3R通过蛋白质 - 蛋白质相互作用或结合DNA影响基因转录。共免疫沉淀和染色质免疫沉淀将用于识别核NK3R的核靶标。 AIM 3将检查持续高渗对PVN中NK3R和NKB mRNA调控的影响。 AIM 4将确定NK3R配体（NKB）的释放来源。结果将鉴定NKB SOMA固有的PVN或该项目对大细胞PVN神经元的项目，并被高渗性激活。总体而言，结果将为膜结合的受体提供新的见解，该受体充当核转录因子和控制巨细胞神经元功能的神经递质系统。 VP释放的功能障碍有助于人类病理生理，例如充血性心力衰竭，结果可能表明对与NK3R系统相关的人类病理学基因组基础的新型治疗策略和/或新见解。公共卫生相关性拟议的研究有可能为应对神经内分泌激素失调的疗法做出贡献，这些神经内分泌激素会导致诸如充血性心力衰竭和高血压等病理。神经激素受体对细胞核的核转运是新颖的，对与大脑中该受体系统有关的大量病理（例如癫痫）具有影响。