Expression Of Annexin-A1 In Peri-Implantation Of Mouse Uterus

AnxA1 is a member of Annexins supper family, and a structurally related calcium dependent phospholipid binding protein. AnxA1 is a multi-performance protein involved in cell signal transduction, proliferation, differentiation, apoptosis, membrane fusion, and other important biological activities. During embryo implantation, cell migration, adhesion and interactions are extremely important. Embryo keeping on differentiation, proliferation and invasion during implantation, while uterine decidual cells undergoing differentiation, proliferation and apoptosis,suggests AnxA1 may play a important role in. AnxA1 is the only known major immunoreactive protein in the rabbit's reproductive system, also plays a role in the sperm acrosome reaction of sheeep and mouse, but the role AnxA1 playing in female mouse's reproductive system is remain to study.This study was going to investigate AnxA1 expression in the mouse uterus by in situ hybridization.AnxA1 mRNA was detected from days 1 to 4 of pregnancy, of which the highest expression on day 3. When embryo implanted on day 5, AnxA1 mRNA were strongly detected in the sub-luminal stroma immediately surrounding the implanted blastocyst. There was a high level of AnxA1 expression in the primary decidual zone on days 6, and secondary decidual zone on days 7 and 8 of pregnancy. AnxA1 shows the similar expression in the decidual zone of artificially induced decidua uterus , too. AnxA1 mRNA was detected in mice uterus of activation delayed implantation, close to embryo implanted on day 5, indicating that AnxA1 expression is induced by the active blastocyst. Expression of AnxA1 in the pseudopregnant uterus is close to that in the preimplantation uterus, suggests AnxA1 is regulated by maternal factors.All these results suggest that AnxA1 may be important in embryo implantation and decidualization of stromal cells.