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

建立卵母细胞与其卵泡微环境之间沟通的基础：新的动态模型

• 批准号: 9015995
• 负责人: HUGH J CLARKE
• 金额: $ 14.85万
• 依托单位: MCGILL UNIVERSITY HEALTH CTR RES INST
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-15 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9015995
• 关键词: Address; Affect; Age; BMP15 gene; Biological Assay; Cell membrane; Communication; Complement; Coupled; Coupling; Cytoplasmic Filaments; Data; Deposition; Development; Differentiation and Growth; Disease; Environment; Environmental Hazards; Epigenetic Process; Experimental Models; Female; Fertility; Filopodia; Foundations; GDF9 gene; Gene Targeting; Genetic; Germ Cells; Germ Lines; Growth; Growth Differentiation Factor 9; In Vitro; Individual; Infertility; Link; MADH4 gene; Mammals; Mediating; Methods; Modeling; Oocytes; Oogenesis; Ovarian Follicle; Phase; Pluripotent Stem Cells; Process; Proteins; Research; Signal Transduction; Somatic Cell; Staging; Structure; Testing; Therapeutic; Thick; Toxin; Transforming Growth Factor beta; Woman; Zona Pellucida; base; design; environmental agent; extracellular; granulosa cell; high reward; high risk; intercellular communication; mRNA Expression; member; novel; novel strategies

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.

项目总结/摘要 不孕症困扰着大约10%的15至44岁的女性，并且可以由各种各样的疾病引发。 条件，包括疾病、疾病治疗、毒素和年龄。虽然这些条件 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 其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 颗粒细胞受损，不能产生功能性卵母细胞。这种细胞间的通讯是 通过长的细胞质丝，称为transzonal projections（TZPs），从细胞质中延伸出来， 颗粒细胞和穿透厚厚的细胞外被（透明膜），生殖细胞周围，以达到 卵母细胞质膜。虽然TZPs是颗粒细胞和生长的唯一途径， 卵母细胞物理通信，没有研究已经解决何时或如何形成这些独特的结构。我们 初步数据表明，TZP的数量在生长阶段大幅增加， 卵子发生。引人注目的是，与生长中的卵母细胞相邻的颗粒细胞表达高度保守的激活因子， 丝状伪足生长和卵母细胞来源的TGF β超家族成员GDF（生长分化因子）-9 增加从周围颗粒细胞突出的TZP的数量。我们建议TZP是 从围绕生长中的卵母细胞的颗粒细胞中动态发育而来的特化丝状伪足， TZP的形成受卵母细胞分泌的TGF β超家族成员的调节， 在颗粒细胞中通过SMAD4依赖性信号转导。利用基因和体内 通过体外方法，我们将确定GDF-SMAD4信号传导是否调节（i）表达和/或定位 丝状伪足装配因子，（ii）TZP的形成和（iii）卵母细胞和卵母细胞之间的缝隙连接偶联。 颗粒细胞这种新的TZP形成模型与目前的理解有根本的不同，因为它 强调连接卵母细胞与其体细胞环境的物理通讯线路是 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 环境条件会损害卵母细胞的质量。它还将提供一个新的概念平台， 设计和制定新的战略，以挽救妇女的生育能力，并将有助于推动新的努力， 从多能干细胞中获得功能性卵母细胞。