高孕激素促排卵对子代DNA甲基化修饰的影响及其机理的研究

The key point of controlled ovarian hyperstimulation lies in the grasp of LH surge. Our recent studies reported that progesterone was able to be used to prevent premature LH surge during the controlled ovarian stimulation (progestin-primed ovarian stimulation, PPOS) with the advantages of no injection, simple to use and lower risk of ovarian hyperstimulation syndrome (OHSS). PPOS protocol was proved to be effective and more and more wildly used. However, PPOS made the oocyte developed in high progesterone condition, which was different from the natural condition, with high estrogen level and low progesterone level. This difference made clinician worried a lot about the impact of PPOS on the epigenetic risk to the offspring. Our previous study found that the PPOS with normal dose of progesterone had no effect on the DNA methylation modification of imprinted gene, However, PPOS with ten-fold of progesterone would lead lower DNA methylation modification of Snrpn gene. We presumed that PPOS with different dose of progesterone would have different effect on the epigenetic reprogramming and might have health risk to the offspring. Thus, we will definite clearly the impact of PPOS with different dose of progesterone on epigenetic risk in different period of development, and its molecular pathways. This study will provide the scientific basis for promoting the optimization of the PPOS protocol.

如何控制早发LH峰是控制性促排卵技术的核心问题。为了弥补现有控制性促排卵方案的不足，本中心提出了孕酮主导的促排卵（progestin-primed ovarian stimulation, PPOS)方案，该方案有明显的临床治疗效果，并且有用药简单、并发症少等优点。然而PPOS方案将卵泡生长和成熟的环境从生理性以雌激素为主导的状态转为了以孕激素为主导的状态。这一改变是否会影响胚胎的DNA甲基化修饰重建从而对子代的健康产生影响总是令人堪忧。我们前期研究发现:常规量孕激素PPOS促排卵IVF对于小鼠胚胎DNA甲基化并没有影响，但过高剂量孕激素PPOS促排卵IVF会导致小鼠胚胎印记基因Snrpn甲基化异常。本项目拟在现有研究基础上通过近交系小鼠建立PPOS促排卵IVF模型进一步研究PPOS促排卵对子代DNA甲基化修饰及健康的影响并探明其中分子机理，为PPOS方案安全有效地应用于临床提供科学依据。

高孕激素促排卵（PPOS）方案促排卵对卵子生长成熟环境的改变是否会对胚胎表观遗传重编程过程，从而对子代健康造成影响备受关注。本研究借助于单细胞全基因组甲基化测序、单细胞RNA-seq分析手段，探讨了不同剂量孕激素对于胚胎甲基化及基因表达调控的影响。此外，课题组通过动物模型，探讨了不同剂量孕激素对于F1代、F2和F3代子代健康的影响，并通过临床上PPOS促排卵方案IVF出生孩子随访研究数据分析了高孕激素促排卵对于出生子代的出生体重、出生缺陷的影响。项目资助期间，项目负责人以第一作者/最后通讯作者身份在国际一流杂志发表论文6篇，其中单篇影响因子最高达到19.160。共培养博士研究生 2名，硕士研究生 1名。因此，完成了预定的研究目标。