IVF促排卵周期注射hCG日及次日孕酮升高影响子宫内膜容受性机制的研 究

Increasing evidences have shown that premature elevated progesterone on the day of hCG administration was associated with reduced implantation rate in women undergoing IVF treatment, one possible explanation was due to the compromised endometrial receptivity. However, the exact molecular by which high progesterone acts on endometrial receptivity still remains elusive. We were able to confirm in our published previous study that elevated progesterone on the day after hCG administration was also negatively related to implantation rate. We firstly designed this research focusing on both consecutive progesterone measurements (on the day of, and day after hCG administration), to investigate the impact of elevated progesterone on endometrial receptivity. We’ve already obtained a certain primary results, and we’re planning to further investigate whether the adverse effects of high progesterone on endometrial reveptivity was ① partially mediated via its action on adhesion function of the luminal epithelial;and ② partially mediated via its modulation on the genomic profile and function of luminal epithelial and glandular compartment of endometrium. The findings of this research will help to update our knowledge on the mechanism of the implantation, to extend our understanding of the micro-environment of endometrium, and to provide robust evidences for the future changes of clinical treatments in practice.

IVF促排卵周期中注射hCG日孕酮升高可导致胚胎着床率显著降低，研究表明注射hCG日孕 酮升高可能损害了子宫内膜容受性，但确切的分子机制尚不清楚。本课题组前期研究发现注射hCG次日孕酮升高也可导致胚胎着床率显著下降。本课题拟首次在同时关注注射hCG日及次日 孕酮的基础上，研究孕酮升高对子宫内膜容受性的影响。基于已获得的初步结果，我们拟通 过多种技术手段验证：注射hCG日及次日高孕酮可能通过①导致腔上皮粘附功能损害；及② 诱导内膜腔上皮和腺上皮细胞基因表达的改变，进一步损害内膜容受性。本项目的研究结果 ，有利于增进对胚胎着床机制的深入了解，丰富子宫内膜免疫微环境的理论知识，为临床IVF 治疗策略的改变提供坚实的理论依据。

随促排卵理论的完善及胚胎培养技术的提高，试管婴儿胚胎种植率逐步升高但到达30%则无法突破。子宫内膜在胚胎种植过程中的作用被日益重视。本项目组在前期研究中发现注射hCG日及注射hCG次日孕酮均可导致内膜基因表达谱的改变，孕酮升高可显著增加uNK细胞的数量。为更细致的探究内膜不同组分：腔上皮细胞vs腺上皮细胞在高孕激素作用下的不同反应，本项目从以下三个方面深入研究（1）促排卵周期注射hCG日及次日孕酮水平与着床期内膜腔上皮细胞粘附分子（MUC16、αvβ3、OPN）表达的影响; 通过激光显微切割技术，分别获取内膜腔上皮（2）和腺上皮（3）组分，行转录组测序，比较高孕酮vs正常孕酮组腔上皮及腺上皮细胞基因表达的差异。在第（1）部分的研究中我们发现：①促排卵周期注射hCG日及次日高孕酮组着床期内膜腔上皮细胞粘附分子MUC16的表达显著高于正常孕酮组（高孕酮组：147.8 (18.0-230.1) vs 正常孕酮组 61.0（2.3-205.3)，P<0.05）; 而另外两种粘附分子αvβ3和OPN的表达组间则无统计学差异。MUC16在种植窗期的表达受孕激素水平的影响，由此推测MUC16可作为一项新内膜容受性的评价指标，进一步拓展性的研究了MUC16蛋白在另外两个队列（不明原因复发性流产vs正常生育力、IVF激素替代胚胎移植后妊娠vs未妊娠）着床期内膜腔上皮vs腺上皮的表达差异，发现：MUC16在不明原因复发性流产妇女中显著低下（复发性流产组：23.7 (0-300) vs 正常生育力组118.4 (7.7-300)，P<0.05）；在激素替代胚胎移植后妊娠妇女中显著低下(妊娠组：23.1（0-250.3) vs 未妊娠组58.4（0-300)，P<0.001）。在第（2）和（3）部分的研究中，高孕酮vs正常孕酮组在腺上皮中有240个差异表达基因，细胞外基质和细胞粘附通路为受影响最为显著的通路；腔上皮中有114个差异表达基因，免疫反应通路为受影响最为显著的通路。本项目的研究结果丰富了子宫内膜容受性的理论，并首次揭示了子宫内膜不同组分在孕激素作用下的特异性的变化，为临床治疗中改进胚胎移植策略提高胚胎利用率提供坚实的理论依据。