卵源性因子评估及改善胚胎质量的应用与机制研究

Embryo quality is the key factor that determines the therapeutic outcome of in vitro fertilization-embryo transfer (IVF-ET), so embryo assessment and embryo quality improvement have been the important issue in the field of reproductive medicine. Oocyte secreted factors (OSFs), including growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15), which have similar molecular structures and physiological functions, are specifically expressed in oocytes and early embryos, whose roles are both to promote oocyte development and improve embryo quality. Our previous study found the expression of OSFs was closely associated with oocyte competence. If so, can OSFs be used as the objective markers for embryo assessment? In the present study, enzyme-linked immunosorbent assay will be used to detect the concentration of GDF9 and BMP15 in the follicular fluid and spent culture medium. By analysis of the relationship between the OSFs concentration and embryo quality, we aim to explore the value of OSFs in embryo assessment, and find new markers for embryo selection. Moreover, the rat oocyte-cumulus complexes (OCCs) and embryos will be cultured in vitro by the addition of recombinant GDF9 and BMP15 protein and their antagonists. By analyzing the effects of OSFs on the biogenesis, copy number, distribution and functional state of the mitochondria in oocytes, we hope to reveal the molecular mechanisms by which OSFs modulate embryo development in the view of mitochondrial function and energy metabolism pathway. This study will lay the experimental basis for the optimization of embryo culture system so as to improve the embryo quality.

胚胎质量是决定体外受精-胚胎移植技术成败的关键因素,如何准确评估及改善胚胎质量一直是生殖医学领域的重要课题。卵源性因子(OSFs)包括生长分化因子9(GDF9)和骨形成蛋白15(BMP15)，二者具有相似的结构和功能，特异表达于卵母细胞和早期胚胎，生理作用均为促进卵母细胞成熟和后续的胚胎发育。我们前期研究发现OSFs与卵母细胞发育潜能密切相关，那么OSFs能否作为胚胎质量的客观评估指标？本项目拟采用酶联免疫吸附法检测卵泡液和培养液中OSFs浓度并分析其与胚胎质量的关系，探讨OSFs评估胚胎质量的应用价值，为临床优选胚胎发掘新的分子指标。本课题还将构建大鼠胚胎体外培养体系并添加GDF9和BMP15重组蛋白或拮抗剂，研究OSFs对卵母细胞线粒体合成、拷贝数、分布及功能的影响，从卵母细胞能量代谢的角度阐明OSFs调控胚胎发育的分子机制，为优化胚胎培养条件改善胚胎质量提供实验依据。

胚胎质量是决定体外受精-胚胎移植技术成败的关键因素，如何准确评估及改善胚胎质量一直是生殖医学领域的重要课题。卵源性因子(OSFs)包括生长分化因子9(GDF9)和骨形成蛋白15(BMP15)，二者具有相似的结构和功能，特异表达于卵母细胞和早期胚胎，生理作用均为促进卵母细胞成熟和后续的胚胎发育。本项目探讨了卵母细胞、颗粒细胞、卵巢组织、卵泡液和培养液中卵源性因子的表达水平与胚胎质量的关系，发现卵源性因子的表达水平与胚胎质量呈现正相关关系，可以作为胚胎质量评估的分子指标。在胚胎培养液中添加卵源性因子可以改善胚胎质量，其机制之一可能是通过影响卵母细胞的线粒体合成和拷贝数，从而为优化胚胎培养体系提供了实验依据。