A role for hypothalamic astrocytes in neural circuits controlling reproduction

下丘脑星形胶质细胞在控制生殖的神经回路中的作用

• 批准号: 10534797
• 负责人: Chrystian David Phillips
• 金额: $ 4万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10534797
• 关键词: Address; Adult; Affect; Anterior Pituitary Hormones; Astrocytes; Back; Brain; Brain region; CRISPR/Cas technology; Calcium; Cell Culture Techniques; Communication; Contraceptive methods; Coupled; Couples; Data; Diestrus; Dinoprostone; Dynorphins; Electrophysiology (science); Elements; Etiology; Exhibits; Feedback; Female; Fertility; Follicle Stimulating Hormone; Genes; Glial Fibrillary Acidic Protein; Glutamates; Gonadal Steroid Hormones; Gonadotropin Hormone Releasing Hormone; Guide RNA; High Pressure Liquid Chromatography; Homeostasis; Hormone secretion; Hypothalamic structure; Image; In Vitro; Infertility; Information Networks; Investigation; KISS1 gene; Ligands; Luteinizing Hormone; Mediator of activation protein; Metabotropic Glutamate Receptors; Methods; Modeling; Monitor; Morphology; Mus; Nervous System Physiology; Neuraxis; Neuroglia; Neurokinin B; Neuromuscular Diseases; Neurons; Neurosecretory Systems; Output; Ovulation; Pathway interactions; Population; Preoptic Areas; Process; Production; Proestrus; RNA delivery; Receptor Signaling; Regulation; Reproduction; Rodent; Role; Sex Differences; Sex Differentiation; Sexual Maturation; Signal Transduction; Slice; Steroid biosynthesis; Steroids; Structure of nucleus infundibularis hypothalami; Testing; Time; Transgenic Mice; Viral Vector; Work; experimental study; gamma-Aminobutyric Acid; gonad function; in vivo; infertility treatment; knock-down; male; mouse model; nervous system disorder; neural circuit; neural network; neurotransmission; new therapeutic target; receptor; relating to nervous system; reproductive; reproductive function; sex; sex cycle; synaptic function; synaptogenesis; therapeutic target

PROJECT SUMMARY Astrocytes are a glial subtype that are essential for numerous central nervous system functions. Dysregulation of astrocyte function is known to cause a variety of neurological and neuromuscular disorders. Interestingly, disruption of hypothalamic astrocytes has the capability to compromise fertility. Roughly one in five couples in the USA suffer from some type of infertility, thus elucidating the complete circuits underlying reproduction is essential. Gonadotropin-releasing hormone (GnRH) neurons in the preoptic area and hypothalamus form the final common pathway for the central control of fertility. Pulsatile GnRH secretion causes release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the anterior pituitary, activating gonadal functions including steroidogenesis. An afferent network likely governs pulsatile GnRH secretion, including both steroid- sensitive kisspeptin neurons in the arcuate nucleus (KNDy neurons) and glia. Although pulsatile GnRH release is common to male and female reproduction, females exhibit unique processes including reproductive cycles and ovulation that could alter neural-glial interactions. Critically, astrocytes exhibit morphological plasticity and the levels of hypothalamic neuron ensheathment by glia change across cycle stages, pointing to potential astrocytic regulation that varies with respect to cycle stage. Astrocytic mediators like prostaglandin E2 (PGE2) can also regulate GnRH neuron activity, and PGE2 is required for timely sexual maturation and adult reproduction in rodents. To investigate the contexts in which astrocytes regulate reproductive neural circuits, a combination of electrophysiology, calcium imaging, and glial cell cultures will be used. Aim 1 will study if factors including sex, cycle stage, and time of day influence the ability of astrocytes to regulate GnRH and/or KNDy neuron firing rates. In vitro chemogenetic activation of astrocytes via the transduced Gq signaling receptor hM3D(Gq) will be employed to induce intracellular calcium transients that typify endogenous Gq-induced astrocyte activity, while monitoring the activity of identified neurons. In Aim 2, chemogenetic activation of primary astrocyte cultures followed by high-performance liquid chromatography of supernatants will be done to elucidate the gliotransmitter profiles of hypothalamic astrocytes. To compliment this, the endogenous Gq- coupled receptor profiles will be assessed in glial cultures and brain slices transduced with GFAP-GCaMP6f via treatment with candidate Gq ligands. These results will inform my subsequent experiments in which an endogenous Gq-coupled receptor will be knocked down in hypothalamic astrocytes and a gliotransmitter receptor in GnRH neurons, providing a test for the necessity of these components of glial-neural signaling for reproduction in vivo. Completion of the proposed work will clarify roles of astrocytes in the neuroendocrine control of fertility. Elucidating the mechanisms by which astrocytes communicate back-and-forth with GnRH and KNDy neurons will pave the way to identifying potential therapeutic targets to treat types of infertility.

项目总结 星形胶质细胞是一种胶质细胞亚型，对许多中枢神经系统的功能是必不可少的。调控失调 已知星形胶质细胞功能障碍会导致多种神经和神经肌肉疾病。有趣的是， 下丘脑星形胶质细胞的破坏有可能损害生育能力。大约五分之一的夫妇 美国患有某种类型的不孕症，因此阐明了生殖的完整回路是 必不可少的。视前区和下丘脑中的促性腺激素释放激素(GnRH)神经元形成 中央控制生育的最终共同途径。节律性促性腺激素释放激素释放黄体生成素 促黄体生成素和卵泡刺激素(FSH)来自垂体前叶，激活性腺功能 包括类固醇激素的生成。一个传入网络可能控制着GnRH的脉动性分泌，包括类固醇和激素- 弓状核(KNDy神经元)和神经胶质细胞中的Kispeptin敏感神经元。尽管GnRH脉冲式释放 在雄性和雌性生殖中是共同的，雌性表现出独特的过程，包括生殖周期 排卵可能会改变神经-神经胶质的相互作用。重要的是，星形胶质细胞表现出形态可塑性和 下丘脑神经胶质细胞包膜水平在不同周期阶段的变化，指向潜在的 星形胶质细胞的调节作用因周期阶段而异。前列腺素E2(PGE2)等星形细胞介质 也可以调节GnRH神经元的活动，而PGE2是适时性成熟和成年所必需的 在啮齿动物身上繁殖。为了研究星形胶质细胞调节生殖神经回路的背景， 将使用电生理学、钙成像和神经胶质细胞培养的组合。目标1将研究IF因素 包括性别、周期阶段和一天中的时间影响星形胶质细胞调节GnRH和/或KNDY的能力 神经元的放电率。转导GQ信号受体对星形胶质细胞的体外趋化激活作用 HM3D(GQ)将被用来诱导典型的内源性GQ诱导的细胞内钙瞬变 星形胶质细胞的活动，同时监测已识别的神经元的活动。在目标2中，化学生成激活 原代星形胶质细胞培养，然后对培养上清液进行高效液相色谱分析 阐明下丘脑星形胶质细胞的胶质递质谱。作为补充，内生的GQ- 将在胶质细胞培养和用GFAP-GCaMP6f转导的脑切片中评估偶联受体的特征 通过候选GQ配体进行治疗。这些结果将为我随后的实验提供信息，在这些实验中 内源性GQ偶联受体将在下丘脑星形胶质细胞和胶质递质中被击倒 GnRH神经元中的受体，为神经胶质细胞信号转导的必要性提供了一种测试 在体内繁殖。这项拟议工作的完成将阐明星形胶质细胞在神经内分泌中的作用 控制生育率。星形胶质细胞与促性腺激素释放激素相互沟通的机制 KNDy神经元将为确定治疗各种不孕症的潜在治疗靶点铺平道路。