Neural Control of the Prepubertal Ovary

青春期前卵巢的神经控制

• 批准号: 7414858
• 负责人: Sergio R Ojeda
• 金额: $ 34.15万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-05-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7414858
• 关键词: Adult; Affinity; Antral; Attention; Biochemical; Brain-Derived Neurotrophic Factor; Cells; Communication; Competence; Condition; Development; Follicular cyst; Gene Targeting; Growth; Hormonal; Knockout Mice; Laboratories; Length; Mus; NGFR Protein; Nerve Growth Factor Receptors; Nerve Growth Factors; Neurotrophic Tyrosine Kinase Receptor Type 1; Neurotrophic Tyrosine Kinase Receptor Type 2; Oocytes; Ovarian; Ovary; Ovulation; Pathway interactions; Physiological; Polycystic Ovary Syndrome; Production; Protein Isoforms; Protein Overexpression; Receptor Protein-Tyrosine Kinases; Regulatory Pathway; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Staging; System; Technology; Testing; Thinking; Transgenic Mice; base; cDNA Arrays; concept; granulosa cell; intercellular communication; interstitial; intraovarian; jagged1 protein; nervous system development; neuroregulation; neurotrophic factor; neurotrophin 4; neurotrophin 4(5) receptor; nonhuman primate; reproductive; research study; transcriptional coactivator p75

DESCRIPTION (provided by applicant): Much is known about the hormonal mechanisms controlling ovarian development. More recently, a major focus of attention in the field has been the identification of regulatory pathways that, operating within the ovarian microenvironment, contribute to the acquisition of ovarian reproductive competence. Within this framework, our laboratory has developed the concept that neurotrophins (NTs) and their Trk tyrosine kinase receptors, long thought to be exclusively required for the development of the nervous system are also involved in the control of ovarian function. Employing gene targeting approaches we identified trkB, the high-affinity receptor for neurotrophin-4/5 (NT-4/5) and brain-derived neurotrophic factor (BDNF), as a signaling molecule required for early follicular growth and oocyte survival. In addition, we showed that nerve growth factor (NGF) contributes independently to the initiation of follicular growth. Other studies indicated that NGF acting via trkA receptors is also important for ovulation, but that despite this physiological role, an inappropriately sustained increase in intraovarian NGF synthesis results in functional alterations leading to the development of follicular cysts. Based on these findings, the present renewal application proposes the following Specific Aims: 1) To define the TrkB receptor isoform (full-length or truncated) required for early follicle growth and oocyte survival, and identify the cells primarily responsive to TrkB signaling. The objectives of this Aim will be achieved using Cre-loxP technology to specifically disrupt the expression of full-length and truncated TrkB isoforms in either oocytes or granulosa cells. 2) To test the hypothesis that NTs signaling via TrkB receptors promote early follicular growth by supporting an oocyte-to granulosa cell Jagged 1-Notch2 communication pathway. This aim will be achieved with the combined use of cell-specific trkB KOs and cellular/biochemical approaches to define the relationship that exists between TrkB signaling and the Notch2 pathway. 3) To test the hypotheses that while NGF-dependent trkA signaling is required for the normal development of antral follicles and ovulation, an overproduction of NGF compromises the ability of antral follicles to reach a preovulatory stage, and thus establishes conditions leading to the development of polycystic ovaries. To accomplish this Aim we will use transgenic mice that overexpress NGF in a cell specific manner, and mice in which signaling through p75 (the common NT receptor), or trkA (the high-affinity NGF receptor) are conditionally disrupted in ovarian cells. 4) To test the hypothesis that an excess of ovarian NGF creates conditions in the local microenvironment that favor the development of polycystic ovaries in nonhuman primates. To accomplish this Aim we will use a lentiviral delivery system to enhance the production of NGF in the interstitial compartment of the adult nonhuman primate ovary.

描述（由申请人提供）：关于控制卵巢发育的激素机制，人们已经了解很多。最近，该领域关注的一个主要焦点是确定在卵巢微环境中运作、有助于获得卵巢生殖能力的调节途径。在此框架内，我们的实验室提出了这样的概念：神经营养素 (NT) 及其 Trk 酪氨酸激酶受体（长期以来被认为是神经系统发育所必需的）也参与了卵巢功能的控制。采用基因靶向方法，我们确定了 trkB（神经营养蛋白-4/5 (NT-4/5) 和脑源性神经营养因子 (BDNF) 的高亲和力受体）是早期卵泡生长和卵母细胞存活所需的信号分子。此外，我们还发现神经生长因子（NGF）独立地促进卵泡生长的启动。其他研究表明，NGF 通过 trkA 受体发挥作用对于排卵也很重要，但尽管具有这种生理作用，但卵巢内 NGF 合成的不适当持续增加会导致功能改变，导致卵泡囊肿的形成。基于这些发现，本更新申请提出以下具体目标： 1) 定义早期卵泡生长和卵母细胞存活所需的 TrkB 受体亚型（全长或截短），并鉴定主要对 TrkB 信号传导有反应的细胞。该目标将通过使用 Cre-loxP 技术特异性破坏卵母细胞或颗粒细胞中全长和截短的 TrkB 同工型的表达来实现。 2) 检验 NTs 通过 TrkB 受体信号传导通过支持卵母细胞到颗粒细胞 Jagged 1-Notch2 通讯途径促进早期卵泡生长的假设。这一目标将通过结合使用细胞特异性 trkB KO 和细胞/生化方法来定义 TrkB 信号传导和 Notch2 通路之间存在的关系来实现。 3) 检验以下假设：虽然窦状卵泡的正常发育和排卵需要依赖 NGF 的 trkA 信号传导，但 NGF 的过量产生会损害窦状卵泡达到排卵前阶段的能力，从而为导致窦状卵泡的发育创造条件。多囊卵巢。为了实现这一目标，我们将使用以细胞特异性方式过度表达 NGF 的转基因小鼠，以及卵巢细胞中通过 p75（常见 NT 受体）或 trkA（高亲和力 NGF 受体）信号传导被条件性破坏的小鼠。 4) 检验以下假设：过量的卵巢 NGF 会在局部微环境中创造有利于非人灵长类动物多囊卵巢发育的条件。为了实现这一目标，我们将使用慢病毒递送系统来增强成年非人灵长类动物卵巢间质室中 NGF 的产生。