IK细胞因子在小鼠早孕期子宫内膜的表达规律及其在胚胎着床中的作用

通过Real-time PCR、Western blot及免疫组织化学方法分析了IK细胞因子(IK cytokine)在早孕小鼠(妊娠D1~D7)子宫内膜中的表达规律及宫角注射IK细胞因子反义寡聚脱氧核苷酸后对胚胎着床的影响。结果显示,IK细胞因子mRNA表达在D1~D4逐渐升高,于D4达到高峰(P<0.05);Western blot和免疫组织化学结果与Real-time PCR结果基本一致,其蛋白表达在D1~D5逐渐升高,于D5达到高峰(P<0.05);IK细胞因子在D5胚胎着床点的表达显著高于着床旁组织;假孕小鼠子宫内膜IK细胞因子蛋白表达明显低于正常妊娠,且整个假孕过程中没有表达高峰;宫角注射IK细胞因子反义寡聚脱氧核苷酸后24 h和48 h(即D4和D5)子宫内膜IK细胞因子表达明显受到抑制,MHCⅡ抗原表达增强,且胚胎着床数量明显减少(P<0.05),提示IK细胞因子在胚胎着床中发挥着重要作用。

Expression of IK Cytokine in Mouse Uterus of Early Pregnancy and Its Significance in Embryo Implantation

The expression of IK cytokine was investigated in mice endometria during early pregnancy(D1~D7 of pregnancy) and pseudopregnancy using Real-time PCR,Western blot and immunohistochemical analysis,and the effect of IK cytokine on embryo implantation was observed by uterus horns injection of antisense IK cytokine oligodexynucleotides.Our data showed that the expression of IK cytokine mRNA increased gradually from D1 to D4 of pregnancy and reached a peak level at D4 of pregnancy(P<0.05).Western blot and immunohistochemical analysis revealed that the expression of IK cytokine protein increased gradually from D1 to D5 of pregnancy and reached a peak level at D5 of pregnancy(P<0.05).The expression of IK cytokine in the pseudopregnant uterus was significantly lower than that in the normal pregnant uterus and the level of the protein never showed a high peak during the whole pseudopregnancy.The expression of IK cytokine at the implantation site was much stronger than that in the inter-implantation segment at D5 of pregnancy.After 24 h and 48 h of treatment with antisense oligodexynucleotides of IK cytokine,the expression of IK cytokine in the uterus was remarkably inhibited,while the expression of MHCII increased and the number of implanted embryos significantly reduced(P<0.05).These results suggested that IK cytokine played a crucial role in implantation.The suppression of MHCII antigens by IK cytokine was likely to inhibit the fetal-maternal immune responses,contributing to the maintenance of successful pregnancy.