骨桥蛋白(OPN)在围植入期小鼠子宫内膜中的表达

目的 检测骨桥蛋白在围植入期小鼠子宫内膜中的表达,明确OPN表达规律.方法 将清洁级性成熟期昆明小鼠44只,雌性24只,雄性20只,雌性小鼠阴道涂片检查为动情前期,在此期注射PMSG和HCG,4只雌鼠不合笼(孕D0,对照组),用颈椎脱臼法处死,剪取子宫组织,直接液氮保存和福尔马林固定保存,其余的雌:雄小鼠1∶1合笼,次日检查阴栓,发现阴栓计为妊娠第1天.分别于妊娠第4、5、6、7和8天用颈椎脱臼法处死,迅速剖腹,剪取子宫组织予以保存(实验组),采用免疫组化方法和Western-blotting技术分析围植入期小鼠子宫内膜中的骨桥蛋白表达规律,采用RT-PCR技术半定量分析围植入期小鼠子宫内膜骨桥蛋白mRNA表达特征.结果 小鼠整个围植入期子宫内膜中均有OPN表达,但表达的高峰在着床窗口期,即孕D5.孕D0(非孕)子宫内膜的OPN表达较弱,孕D4时表达增强,孕D5时表达最强,孕D6时表达突然回落,孕D7、孕D8时表达减弱,降至非孕水平.结论 骨桥蛋白在围植入期小鼠子宫内膜中的表达随着孕龄的增加逐渐增强,但表达的高峰在孕D5,与植入窗的开放相吻合,是子宫内膜接受性的客观标志,提示骨桥蛋白在胚泡着床过程中起重要作用,该研究为阐明胚泡着床机制提供了实验依据.

Expression of osteopontin in mouse endometrium during peri-implantation

【Objective】 To detect the OPN expression in the peri-implantation mouse endometrium,and the expression profile of OPN.【Methods】 Of 44 mice,24 female mice at proestrus,20 male mice at sexual maturity.Female mice were injected with PMSG and HCG.Four female mice were sacrificed at estrus(Day 0).20 female mice assigned to pregnant status were mated to intact fertile 20 males of the same strain.Uteri were then collected on Day 4,5,6,7,and 8 of pregnancy(n =4 per group;Day 1 defined as the day of vaginal plug).The implantation number of mice blastocyst was counted.Endmetrium tissues were stored at liquid nitrogen or 4% paraformaldehyde.OPN expression was detected using immunohistochemistry and western-blotting.OPN gene expression was analyzed by RT-PCR.【Results】 The results of our study showed that the expression of OPN in mouse endometrium luminal epithelium on Day 0 of pregnancy was very weak,OPN protein expression gradually increased along pregnancy process.OPN gene expression also increased along pregnancy process,the expression of OPN on Day 5 was increased to the extreme,and but on Day 6 was decreased,and on Day 7or Day 8 was decreased dramatically.【Conclusions】 Both gene and protein expression profile of osteopontin show that osteopontin increase along pregnancy process,peaked on Day 5.The expression of osteopontin in mouse endometrium frames the "implantation window",which is a candidate biochemical marker of uterine receptivity.This indicates that osteopontin involve in embryo implantation.This provides a novel clue for elucidating mechanism of embryo implantation.