Nutritional Regulation of Luteinizing Hormone Secretion

项目摘要 拟议研究的长期目标是确定核心机制， 营养不足和恢复通过调节促性腺激素释放影响生殖 激素（GnRH）和促黄体生成激素（LH）分泌，使用雄性和雌性绵羊作为动物 模型青春期的开始整合了各种内部和外部的线索，导致增加释放 来自下丘脑的GnRH，赋予性成熟和生殖成功的能力。 能量摄入不足（营养不良）对GnRH有显著的负面影响， LH分泌，从而延缓青春期的开始。然而，负责执行《公约》的中央机制 营养不良期间GnRH/LH分泌抑制或营养不良后GnRH/LH分泌增加 再喂养（再结合）仍然是未知的。因此，本提案的目标是：1） 确定AgRP信号在调节GnRH和kisspeptin神经元中的作用， 营养不良和realimentation，和2）确定的作用，小胶质细胞在调节GnRH和 kisspeptin神经元在营养不足和realimentation。在目标1中，我们将描述 在限食（FR）绵羊的GnRH和kisspeptin神经元中的AgRP信号传导，检查体内效应 下丘脑弓状核（ARC）AgRP免疫中和对FR LH分泌的影响 羊，并表征在饲养绵羊的GnRH和kisspeptin神经元中AgRP信号传导的变化。在 目的2：研究FR中GnRH和kisspeptin神经元中枢免疫信号的变化 绵羊，研究了中枢输注白细胞介素-1受体拮抗剂对LH分泌的体内作用 在FR绵羊中，表征了喂食后GnRH和kisspeptin神经元中枢免疫信号传导的变化， 绵羊，并检测低葡萄糖和胰岛素对小胶质细胞表型和功能的体外影响。 在此，凭借我们在整体动物生理学、体内药物递送、免疫组织化学和免疫组织化学方面的专业知识， 体外细胞培养，我们设计了实验，应用高度创新的荧光技术， 原位杂交试验，RNAscope，用于检测AgRP（Aim 1）的信号组分， 白细胞介素1β（Aim 2）。拟议的实验不仅将解决神经网络， 代谢状态的变化影响生殖，但也提供了重要的洞察力的作用，免疫 系统可能会玩。因此，这项工作将使人们更好地了解营养不良如何影响 调节GnRH/LH分泌的中枢网络，并产生新的和关键的见解， 更好地控制青春期的时间，并最终通过预防 与青春期延迟相关的疾病（如心血管疾病和抑郁症）。

Project Summary The long-term goal of the proposed research is to determine the central mechanisms by which undernutrition and realimentation impact reproduction through regulation of gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) secretion, using male and female sheep as an animal model. Puberty onset integrates various internal and external cues resulting in an increased release of GnRH from the hypothalamus that imparts the capacity for sexual maturation and reproductive success. Inadequate energy intake (undernutrition) has a significant negative impact on GnRH, and subsequently LH secretion, thereby delaying puberty onset. However, the central mechanisms responsible for the suppression of GnRH/LH secretion during undernutrition or the increase of GnRH/LH secretion following re-feeding (realimentation) remain largely unknown. Thus, the objectives of this proposal are 1) to determine the role that AgRP signaling plays in regulating GnRH and kisspeptin neurons during undernutrition and realimentation, and 2) to determine the role that microglia play in regulating GnRH and kisspeptin neurons during undernutrition and realimentation. In Aim 1, we will characterize changes in AgRP signaling in GnRH and kisspeptin neurons in feed-restricted (FR) sheep, examine the in vivo effect of AgRP immunoneutralization in the arcuate nucleus (ARC) of the hypothalamus on LH secretion in FR sheep, and characterize changes in AgRP signaling in GnRH and kisspeptin neurons in refed sheep. In Aim 2, we will characterize changes central immune signaling in GnRH and kisspeptin neurons in FR sheep, examine the in vivo effect of central infusion of an interleukin-1 receptor antagonist on LH secretion in FR sheep, characterize changes in central immune signaling in GnRH and kisspeptin neurons in refed sheep, and examine the in vitro effect of low glucose and insulin on microglia phenotype and function. Herein, with our expertise in whole-animal physiology, in vivo drug delivery, immunohistochemistry, and in vitro cell culture we have designed experiments to apply the highly innovative technique of a fluorescent in situ hybridization assay, RNAscope, for detection of signaling components for AgRP (Aim 1) and interleukin-1β (Aim 2). The proposed experiments will not only address the neuronal networks by which changes in metabolic state impact reproduction, but also provide important insight into the role the immune system likely plays. Thus, this work will provide a greater understanding of how undernutrition impacts central networks that regulate GnRH/LH secretion and yield novel and critical insight that may allow for better control of the timing of puberty, and ultimately lead to improved human health through prevention of disorders (e.g. cardiovascular disease and depression) associated with delayed puberty.