Extracellular ATP Metabolism as a Novel Regulator of Gonadotrope Cell Function

细胞外 ATP 代谢作为促性腺细胞功能的新型调节剂

• 批准号: 9143789
• 负责人: MARK S ROBERSON
• 金额: $ 23.02万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-11 至 2018-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9143789
• 关键词: ATP phosphohydrolase; Anabolism; Anterior Pituitary Gland; Attention; Behavior; Biological Models; Biotinylation; Brain; Cell membrane; Cell model; Cell physiology; Cell surface; Complex; Contraceptive methods; Critical Pathways; Cytochrome c Reductase; Electron Transport; Endocrine; Enzymes; Equilibrium; Estrous Cycle; Extracellular Space; Female; Fertility; G-Protein-Coupled Receptors; Genus Hippocampus; Gonadotrope Cell; Gonadotropin Hormone Releasing Hormone; Gonadotropin-Releasing Hormone Receptor; Gonadotropins; Health; Hormones; Hypothalamic structure; Immunofluorescence Immunologic; Mammals; Mediator of activation protein; Membrane; Metabolism; Mitochondria; Modeling; Multienzyme Complexes; Mus; Neurons; Neurosecretory Systems; Nucleotides; Ovulation; Oxygen Consumption; Peptides; Physiological; Pituitary Gland; Play; Proteomics; Proton-Translocating ATPases; Protons; Regulation; Reproduction; Research; Role; Sampling; Sheep; Signal Transduction; Staging; Succinate Dehydrogenase; Synaptic Transmission; Work; base; enzyme activity; extracellular; flotillin; gonad function; hormone sensitivity; in vivo; innovation; metabolic abnormality assessment; novel; paracrine; proliferative phase Menstrual cycle; reproductive axis

 DESCRIPTION (provided by applicant): Gonadotropin releasing hormone (GnRH) is the central neuroendocrine mediator controlling the biosynthesis and secretion of gonadotropic hormones. The GnRH receptor (R) serves as the central integrator of hypothalamic signals to coordinate gonadotrope behavior in vivo. In the absence of this critical neuroendocrine interface, reproduction ceases. The GnRHR is a unique G-protein-coupled receptor that displays constitutive plasma membrane localization in raft compartments; this membrane compartmentalization is required for efficient cell signaling to pathways critical for fertility in female mammals. In this revised application, we focus our attention on the novel identification of co-localization of the F0F1 ATP synthase complex and enzymes in the electron transport chain with the GnRHR within membrane rafts in pituitary gonadotropes. Unique preliminary proteomic studies in this exploratory R21 application have identified a suite of 129 peptides that specifically localize with the GnRHR at the plasma membrane providing a vigorous opportunity to explore how these membrane-associated complexes control GnRH action and potentially fertility. Preliminary studies in support of the proposed research plan focus on the functional importance of the F0F1 ATP synthase complex identified at the cell surface through interactions with the GnRHR and the membrane raft marker flotillin 1 in a gonadotrope cell model system. These studies demonstrate that the gonadotrope can actively synthesize and metabolize ATP extracellularly. Further, extracellular ATP tone modulates GnRH-induced secretion of LH from mouse pituitaries in explant culture. Based upon these preliminary studies, our central working hypothesis that activation of the GnRHR within membrane rafts is modulated by extracellular ATP through the actions of F0F1 ATP synthase and ectoNTPDase CD39 as paracrine effectors at the cell surface. ATP paracrine modulation of GnRH action will impact the secretion of LH. The following Specific Aims examine this central working hypothesis: Aim 1. Analyze the role of the electron transport chain in regulating cell surface F0F1 ATP synthase activity in gonadotropes. Aim 2. Determine the physiological importance of the ectoNTPDase CD39 in modulating GnRH action. Aim 3. Define the origin of F0F1 ATP synthase metabolites in the extracellular space.

 描述（由申请人提供）：促性腺激素释放激素（GnRH）是控制促性腺激素生物合成和分泌的中枢神经内分泌介质。GnRH受体（R）充当下丘脑信号的中央整合者，以协调体内促性腺激素的行为。如果缺乏这个关键的神经内分泌界面，GnRHR 就会停止，它是一种独特的 G 蛋白偶联受体。显示筏隔室中的组成型质膜定位；这种膜区室化是有效的细胞信号传导至生育关键途径所必需的 在这个修订后的申请中，我们将注意力集中在电子传递链中的 F0F1 ATP 合酶复合物和酶与垂体促性腺激素膜筏内的 GnRHR 共定位的新鉴定上。 R21 应用已鉴定出一组 129 种肽，这些肽与质膜上的 GnRHR 特异性定位，为探索这些膜相关复合物如何发挥作用提供了有力的机会。支持拟议研究计划的初步研究重点是通过与促性腺激素细胞模型系统中的 GnRHR 和膜筏标记 flotillin 1 相互作用在细胞表面识别出的 F0F1 ATP 合酶复合物的功能重要性。这些研究表明，促性腺激素可以在细胞外主动合成和代谢 ATP。此外，细胞外 ATP 调节 GnRH 诱导的小鼠 LH 分泌。基于这些初步研究，我们的中心工作假设是膜筏内 GnRHR 的激活是通过 F0F1 ATP 合酶和 ectoNTPDase CD39 作为细胞表面 ATP 旁分泌效应子的作用来调节的。 GnRH 作用将影响 LH 的分泌 以下具体目标检验了这一中心工作假设： 目标 1. 分析电子传递的作用。目标 2. 确定 ectoNTPDase CD39 在调节 GnRH 作用中的生理重要性。 目标 3. 定义细胞外空间中 F0F1 ATP 合酶代谢物的起源。