NEURAL CONTROL OF THE PREPUBERTAL OVARY

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 人们对控制卵巢发育的荷尔蒙机制知之甚多。 最近，该领域的一个主要关注焦点是确定 在卵巢微环境中运行的调节通路，有助于 卵巢生殖能力的获得。在这个框架内，我们的 实验室已经发展出神经营养因子(NTS)及其Trk酪氨酸的概念 激酶受体，长期以来被认为是唯一需要的发育 神经系统也参与了卵巢功能的控制。用人基因 靶向方法我们确定了TrkB，神经营养因子的高亲和力受体- 4/5(NT-4/5)和脑源性神经营养因子(BDNF)作为信号分子 是早期卵泡生长和卵母细胞存活所必需的。此外，我们还展示了 神经生长因子(NGF)在卵泡启动中的独立作用 成长。其他研究表明，通过TrkA受体发挥作用的NGF也很重要 排卵，但尽管这种生理作用，一个不适当的维持 卵巢内NGF合成增加导致功能改变，导致 卵泡囊肿的发生。根据这些调查结果，目前的更新 申请提出了以下具体目标：1)定义TrkB受体 早期卵泡生长和卵母细胞存活所需的亚型(全长或截短)， 并识别主要响应TrkB信号的细胞。这一目标的目标 将使用Cre-loxP技术来实现特定干扰表达 在卵母细胞或颗粒细胞中存在全长和截短的TrkB亚型。2)测试 NTS信号通过TrkB受体促进早期卵泡生长的假说 通过支持卵母细胞到颗粒细胞的参差不齐的1-Notch2通讯通路。 这一目标将通过结合使用特定于细胞的TrkB KO和 细胞/生化方法来定义TrkB之间存在的关系 信号和Notch2途径。3)检验假设：当NGF- 有腔卵泡的正常发育需要依赖的TrkA信号 而排卵，NGF的过度产生会损害有腔卵泡的能力 达到排卵前阶段，从而创造条件导致 多囊卵巢的发育。为了实现这一目标，我们将使用转基因小鼠 以细胞特有的方式过表达NGF，而小鼠通过 P75(常见的NT受体)或TrkA(高亲和力的NGF受体)是 卵巢细胞的条件性破坏。4)检验假设 卵巢NGF在局部微环境中创造条件，有利于 非人灵长类动物多囊卵巢的发育。为了实现这一目标，我们 将使用慢病毒递送系统来增强NGF在 非人灵长类成年卵巢的间隔室。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. 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.