Spatiotemporal expression of S100A2 in peri-implantation mouse endometrium

Objective:To identify the expression pattern of S100A2 mRNA and protein in peri-implantation endometrium in mice,and to accumulate experimental proof which S100A2 might play roles in embryo implantation.Methods:mRNA and protein expression of S100A2 were detected by fluorescence quantitative polymerase chain reaction(FQ-PCR) and immunohistochemistry.Results:① S100A2 mRNA was steadily expressed in the mouse uterus during d1-d6 of pregnancy,and its quantity gradually decreased day by day.On d5 of pregnancy,its expression level was lower in the implantation sites than that in inter-implantation sites.②S100A2 protein was localized in cytoplasm of mouse endometrial stromal cells,while its level dynamically changed:strongly positive on d1-d2,weakly positive on d3-d5.③No expression was detected in endometrial luminal epithelial cells and gland cells.Conclusion:Dynamic expression of S100A2 in mouse uterus during embryo implantation shows that it might play roles in regulation of embryo invasion into the uterine endometrium.