整合素β_3在围植入期小鼠子宫内膜中的表达

Expression of integrin β3 in mouse endometrium during peri-implantation

目的检测整合素β3在围植入期小鼠子宫内膜中的表达,明确整合素β3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,用颈椎脱臼法处死,剪取子宫组织(孕D0,对照组),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整合素β3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整合素β3mRNA表达特征。结果小鼠整个围植入期子宫内膜中均有整合素β3表达,但表达的高峰在着床窗口期,即孕D5。孕D0(非孕)子宫内膜的整合素β3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。结论整合素β3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,提示整合素β3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实验依据。

[ Objective ] To detect integfin 13s expression in the peri-implantation mouse endometrium, and the ex- pression profile of integrin 133. [ Methods ] Of 44 mice, 24 female mice at proestrus, 20 male mice at sexual maturi- ty, 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 was defined as the day of vaginal plug）. The implanta- tion number of mice blastocyst was counted. Endmetrium tissues were stored at liquid nitrogen or 4.00% paraformaldehyde. Integrin β3 expression was detected using immunohistochemistry and western-blotting. Integrin 133 gene expression was analyzed by RT-PCR. [Result] The result of our study showed that the expression of integrin in mouse endometrium luminal epithelium on day 0 of pregnancy was very weak, integrin [33 protein expression gradually increased with pregnancy process. Integrin [33 gene expression also increased with pregnancy process, the expression of integrin 13s on day 5 was increased to the extreme, and but on day 6 was decreased, and on day 7 or day 8 was decreased dramatically. [ Conclusion ] Both gene and protein expression profile of integrin β3 showed that integrin β3 increased along pregnancy process, reached the peak on day 5. The expression of integrin β3 in mouse endometrium frames the ＂implantation window＂, which is a candidate biochemical marker of uterine receptiv- ity. This indicates that integrin 133 involve in embryo implantation. This provides a novel clue for elucidating mecha- nism of embryo implantation.