小鼠子宫中谷胱甘肽过氧化物酶3（GPX3）的调节及其与蜕膜化的关系

Reactive oxygen species (ROS)can lead to oxidative stress and is involved in many diseases and senescence. Hydrogen peroxidase (H2O2) is one of ROS family and can cause DNA damage. Glutathione peroxidase 3 (GPX3) is one of the key enzymes in the cellular defense against oxidative stress through reducing H2O2.Based on our preliminary data, GPX3 expression at implantation site is significantly increased than inter-implantation site,and H2O2 amount at implantation site is lower than that at inter-implantation site, suggesting that GPX3 may play a key role against oxidative stress during embryo implantation. This study is to analyze the followings: (1)GPX3 expression and regulation in mouse uterus under early pregnancy, pseudopregnancy, delayed implantation, artificial decidualization and hormonal treatments; (2)The regulation of H2O2 level and decidualization by GPX3; (3) GPX3 regulation by implantation-related transcription factors and miR-138; (4) Effects of Gpx3 knockout on embryo implantation and decidualization; (5) Effects of hypoxia and high temperature on embryo implantation and decidualization in Gpx3 knockout mice. The data from this study will be valuable for further understanding on embryo implantation.

活性氧（ROS）可引起氧化应激等，与很多疾病和衰老的发生有关。过氧化氢（H2O2）为活性氧的重要一员，可破坏细胞的内稳态，导致DNA损伤等。谷胱甘肽过氧化物酶3（GPX3）可将H2O2还原为水，是一个起关键作用的抗氧化酶。我们的初步结果显示，与非着床位点相比，GPX3在小鼠妊娠第5天子宫的着床位点显著上调，并且着床位点处的H2O2含量显著低于非着床位点，暗示GPX3可能在清除胚胎着床位点处的氧化应激过程中起重要作用。本课题将主要研究以下问题：（1）在早期妊娠、假孕、延迟着床与激活、人工诱导蜕膜化及类固醇激素调节等条件下，GPX3在小鼠子宫中的表达和调节规律；（2）GPX3对H2O2水平的调节及其与蜕膜化的关系；（3）研究胚胎着床相关因子及miR-138对于GPX3的调节；（4）利用GPX3基因敲除小鼠研究GPX3在小鼠蜕膜化过程中的功能；（5）缺氧和高温等条件对于胚胎着床和蜕膜化的影响。

基于我们前期的基因芯片分析结果，谷胱甘肽过氧化物酶3在小鼠胚胎着床位点显著上调，但有关GPX3在小鼠胚胎着床及蜕膜化过程中的表达、调节及功能仍不清楚。我们通过原位杂交证实，与非着床点相比，GPX3在小鼠胚胎着床位点处上皮下基质细胞中的特异性表达，这种特异表达在延迟着床及假孕的子宫中并未检测到。通过分析子宫中H2O2水平发现，胚胎着床点处H2O2水平显著低于非着床点。在卵巢切除小鼠中，雌激素及孕酮均可上调GPX3的表达。在体外蜕膜化过程中，H2O2的水平也显著降低。我们结合位点预测及报告载体分析也证实，miR-138可特异性调节GPX3的表达。用GPX的特异抑制剂处理妊娠小鼠，可显著抑制小鼠的蜕膜化过程。本课题共计发表SCI论文10篇。这些结果对于了解蜕膜化机理以及治疗不孕症等具有一定参考价值。