MTOR介导的卵母细胞-颗粒细胞调控环路影响卵母细胞质量与颗粒细胞命运的机制研究

The quality of oocytes and the endocrine functions of ovarian somatic cells are key determinants of females' reproductive potential and health. The development and functions of oocytes and granulosa cells are controlled by multiple factors and complex signals existing both within and outside of them, which include hormones, growth factors, nutrients and stress, as well as the interactions between the oocytes and the companion granulosa cells. However, how the oocyte and its companion granulosa cells integrate these factors and signals to coordinate their development remains poorly understood. MTOR is a widely recognized key integrator of such cues important for the control of cell growth and differentiation, but its specific roles and the underlying mechanisms in controlling oocyte and granulosa cell development are still not known. Here, based on our recent findings on the involvement of MTOR in the interaction between oocytes and granulosa cells and its essential roles in the control of oocyte and granulosa cell development, we propose to further explore the mechanisms by which MTOR determines oocyte quality and granulosa cell fate, and to identify key genes that are downstream of MTOR and essential for oocyte acquisition of meiotic and developmental competence.

卵子质量与卵泡体细胞的内分泌功能是影响女性生育能力及生殖健康的关键。卵母细胞及颗粒细胞的发育与功能受到其内外多种因素(诸如：激素、生长因子、营养供应以及应激等)以及两种细胞之间交互作用的复杂调控。然而，卵母细胞与颗粒细胞如何整合这些因素进而协同调控彼此的发育尚不明了。MTOR被广泛认为是细胞用以整合上述复杂因素进而调控其生长发育的关键信号分子，但其在卵母细胞及颗粒细胞中的具体作用及机制还不清楚。本项目在前期发现MTOR通路介导卵母细胞-颗粒细胞交互作用并对两种细胞具有重要调控功能的基础上，拟利用卵母细胞与颗粒细胞特异性Mtor敲除小鼠模型，并结合RiboTag/RIP-Seq和RNA-Seq等技术深入研究MTOR通路调控卵母细胞及颗粒细胞发育，进而影响卵母细胞质量和控制颗粒细胞命运的机制，并探寻两种细胞内受MTOR通路调控并对卵母细胞减数分裂及发育潜能起重要调控作用的关键基因。

女性生育能力及生殖健康在很大程度上取决于卵母细胞的质量和卵泡体细胞的内分泌功能。卵母细胞与其周围的卵泡体细胞（即颗粒细胞）的发育与功能受到两种细胞内外多种因素，诸如：激素、生长因子、营养供应以及应激等，以及两种细胞之间对话交流的复杂调控。然而，这两种细胞如何整合这些因素进而协同调控彼此的发育尚不清楚。MTOR通路被广泛认为是细胞用以整合上述复杂因素进而调控其生长发育的关键信号，但其在卵母细胞及颗粒细胞中的具体作用及机制还不明了。本项目在前期发现MTOR通路介导卵母细胞-颗粒细胞交互作用并对两种细胞具有重要调控功能的基础上利用卵母细胞与颗粒细胞内Mtor基因特异性敲除与RiboTag小鼠遗传学模型并结合体外细胞培养体系以及微量样品RIP-Seq 和RNA深度测序等先进技术，深入研究了MTOR通路介导卵母细胞-颗粒细胞互作进而影响卵母细胞质量与颗粒细胞命运的作用和机制。项目研究发现颗粒细胞内的MTOR信号在维持卵母细胞-颗粒细胞发育的同步化，避免过早诱导卵丘扩展和卵母细胞成熟这一排卵过程关键事件的发生方面发挥重要功能；同时颗粒细胞内的MTOR通路参与维持卵泡正常发育与防止卵巢早衰，并且对于卵母细胞发育潜能的获得具有不可或缺的促进作用。卵内的MTOR通路可以通过调控卵母细胞内蛋白的翻译活动而影响卵母细胞的质量和颗粒细胞的命运，其中处于非生长静止状态的原始卵泡卵母细胞内的MTOR通路通过调控某（些）旁分泌因子的产生而控制着早期颗粒细胞的基因表达和命运。这些发现为深入研究早期卵泡发育过程中卵母细胞-颗粒细胞对话以及颗粒细胞命运决定的调控机制提供了新的思路，为进一步揭示卵母细胞发育成熟和质量决定的分子机制奠定了坚实的基础