p16INK4a在早孕小鼠子宫内膜的表达及其对胚泡着床的影响

本研究旨在检测肿瘤抑制基因p16INK4a(inhibitor of cyclin-dependent kinase 4a)在早孕小鼠子宫内膜中的表达规律,探讨p16INK4a在小鼠胚胎着床过程中的作用.采用荧光定量PCR(FQ-PCR)和免疫组织化学方法分别检测未孕小鼠及孕小鼠第2、3、4、5、7天子宫内膜p16INK4a mRNA和蛋白的表达;子宫角注射p16INK4a抗体观察胚泡着床数.FQ-PCR结果显示孕小鼠子宫内膜组织p16INK4amRNA的表达高于未孕小鼠,且随着妊娠天数的增加呈现表达逐渐增强的趋势,到妊娠第5天达到最高,后渐降.免疫组织化学分析显示p16INK4a蛋白在子宫内膜的表达规律与mRNA结果一致.子宫角注射p16INK4a抗体后胚泡着床数明显减少.以上结果提示,P161INK4a在妊娠早期子宫内膜持续表达,可能参与胚泡着床.

Expression of p16INK4a in mouse endometrium and its effect during blastocyst implantation

The expression of tumor suppressor gene p16(INK4a) in mouse endometrium during early pregnancy and its possible role in blastocyst implantation were investigated in the present study. Real-time fluorescent quantitative PCR (FQ-PCR) and immunohistochemistry were applied to detect p16(INK4a) mRNA and protein expressions in endometrium of un-pregnant and pregnant mice on day 2, 3, 4, 5, 7, respectively. In addition, p16(INK4a) antibody was injected into the horns of uteri in pregnant mice on day 3 and its effect during blastocyst implantation was detected in vivo. The higher expressions of p16(INK4a) mRNA and protein were observed in pregnant mice compared with that in un-pregnant mice, with a steady increase from day 2 to day 5 and reaching the maximal level on day 5 of pregnancy and then decreasing. p16(INK4a) antibody decreased the number of implanted blastocysts compared with that of saline-injected group. The results suggest that p16(INK4a) may be associated with apoptosis of luminal epithelial cells and decidual cells, coordinating decidualization of endometrium and invasion of trophoblastic cells. Thus, we presume that p16(INK4a) participates in the process of blastocyst implantation in mice.