Establishing the foundation for communication between the oocyte and its follicular microenvironment: a new dynamic model

项目摘要/摘要 在15岁至44岁的女性中，约有10%的人患有不孕症，并可由多种疾病引发 条件，包括疾病、疾病的治疗、毒素和年龄。尽管这些条件 通常通过影响卵母细胞的质量来损害生育能力，我们对卵母细胞如何与 它所处的环境阻碍了有效治疗策略的发展。卵母细胞发育 完全依赖于与卵泡中的体细胞颗粒细胞的接触。当与客户进行沟通时 颗粒细胞受损，不能产生功能性卵母细胞。这种细胞间的通信是 通过长的细胞质细丝，称为跨带投射(TZPs)，从 颗粒细胞并穿透围绕生殖细胞的厚厚的细胞外衣(透明带)到达 卵母细胞质膜。尽管TZP是颗粒细胞和生长的唯一途径 尽管卵母细胞在物理上相互交流，但还没有研究表明这些独特的结构是何时或如何形成的。我们的 初步数据显示，开发区的数量在#年增长阶段大幅增加。 卵子发生。值得注意的是，与正在发育的卵母细胞相邻的颗粒细胞表达高度保守的激活物 丝足生长与卵母细胞来源的转化生长因子β超家族成员生长分化因子-9 增加周围颗粒细胞突起的TZP数量。我们建议把分区计划大纲图 特殊的丝状伪足，由生长中的卵母细胞周围的颗粒细胞动态细化而成 TZP的形成受卵母细胞分泌的转化生长因子β超家族成员的调节，其作用是 在颗粒细胞中通过Smad4依赖的信号转导。使用基因和基因的组合 体外方法，我们将确定GDF-Smad4信号是否调节(I)表达和/或定位 丝轴组装因子，(Ii)TZP的形成和(Iii)卵母细胞与细胞之间的缝隙连接耦合 颗粒细胞。这种新的TZP形成模式与目前的理解有根本的不同，因为它 强调将卵母细胞与其躯体环境联系起来的物理通信线路是 动态结构，因此受到遗传和表观遗传的影响。它将建立一个新的 了解如何-通过影响TZP的形成、功能或稳定性-疾病和 环境条件会影响卵母细胞的质量。它还将提供一个新的概念平台 设计和制定新的战略来挽救妇女的生育能力，并将有助于推动新的努力 来自多能干细胞的功能性卵母细胞。

PROJECT SUMMARY / ABSTRACT Infertility afflicts about 10% of women between the ages of 15 and 44 and can be triggered by a wide range of conditions, including disease, therapeutic treatment for disease, toxins, and age. Although these conditions often impair fertility by affecting oocyte quality, our limited understanding of how the oocyte communicates with its environment has hampered the development of effective therapeutic strategies. Oocyte development depends absolutely on contact with somatic granulosa cells in the ovarian follicle. When communication with the granulosa cells is impaired, functional oocytes are not produced. This intercellular communication is mediated through long cytoplasmic filaments, termed transzonal projections (TZPs), that extend from the granulosa cells and penetrate the thick extracellular coat (zona pellucida) that surrounds the germ cell to reach the oocyte plasma membrane. Although TZPs are the sole means by which the granulosa cells and growing oocytes physically communicate, no research has addressed when or how these unique structures form. Our preliminary data indicates that the number of TZPs increases substantially during the growth phase of oogenesis. Strikingly, the granulosa cells adjacent to growing oocytes express highly conserved activators of filopodial growth, and the oocyte-derived TGFβ superfamily member, GDF (growth-differentiation factor)-9 increases the number of TZPs projecting from the surrounding granulosa cells. We propose that TZPs are specialized filopodia that are dynamically elaborated from the granulosa cells surrounding growing oocytes and that TZP formation is regulated by TGFβ superfamily members secreted by the oocyte whose effect is transduced through SMAD4-dependent signaling in the granulosa cells. Using a combination of genetic and in vitro approaches, we will determine whether GDF-SMAD4 signaling regulates (i) expression and/or localization of filopodial assembly factors, (ii) TZP formation and (iii) gap junctional coupling between the oocyte and the granulosa cells. This new model of TZP formation differs fundamentally from current understanding because it emphasizes that the physical lines of communication that link the oocyte to its somatic environment are dynamic structures, and therefore are subject to genetic and epigenetic influences. It will establish a new paradigm for understanding how – by influencing TZP formation, function or stability – disease and environmental conditions can compromise oocyte quality. It will also provide a novel conceptual platform for designing and developing new strategies to rescue fertility in women and will help propel new efforts to derive functional oocytes from pluripotent stem cells.