MK Gene Regulates Apoptosis Of Mouse Decidual Stromal Cells

Blastocyst implantation is one of the earliest events in the reproduction of humans and mammals that determines whether pregnancy will develop up to term. Successful implantation depends on blastocyst invasion, endometrium acceptivity and their synchronized development. Endometrial receptive changes include plenty of complicate regulatory factors involving inregulating cell proliferation, apoptosis and other complicate molecular events. TRAIL is one member of the tumor necrosis factor (TNF) family, and can induce apoptosis of tumor cells by binding its death receptors of which MK is the unique death receptor in mice. Decidua,transformed from endometrial stroma, which share many characteristics of cancer cells such as macronucleus and multinucleus, is crucial for successful blastocyst implantation and the maintenance of pregnancy. MK has been proved to be expressed in the decidual cells. Here, MK was speculated to participate in the apoptosis of decidual cells.Objectives: To provide novel evidence to clarify the molecular mechanism of embryo implantation, molecular clonging, immunocytochemistry, flow cytometry and other methods were used to explore the regulatory role of MK on mouse uterine decidual cells.Methods: 1.The recombinant MK adenovirus were constructed,for further application. 2.Uterine stromal cells were extracted from uterus of mice at d4 of pregnancy and artificially induced into decidualization in vitro.3. Prolactin was detected by immunocytochemical staining in decidual stromal cells transfected with MK over-expression and siRNA recombinant adenovirus, respectively;4. The rates of apoptosis of decidual stromal cells, transfected with MK overexpression and siRNA recombinant adenovirus, was examined by flow cytometry. 5. The number of implantating embryos in uterine horns injected with adenovirus was recorded and analyzed.Results: 1.The recombinant MK adenoviral vectors were correctly constructed and the titer of the over-expression adenovirus was 5.3×1011pfu/ml while the titer of the small interfering adenovirus was 6.8×1011pfu/ml. 2.Immunocytochemical detection showed that the prolactin in decidual stromal cells decreased after transfected with MK over-expression adenovirus and increased with MK siRNA adenovirus. 3.Relative apoptotic percentage detected by flow cytometry showed that it increased after transfected with MK over-expression adenovirus and it decreased after transfected with MK siRNA adenoviru(sP<0.05). 4.Uterine horn injection of MK over-expression or siRNA adenovirus lead to significant reduction of the number of implanting embryos at d8 of pregnancy in mice(P<0.05).Conclusions: 1.The recombinant MK adenovirus were correctly constructed. 2. MK is capable of inducing apoptosis of decidual stromal cells and it may play an important role in regulating the progress of decidual stromal cells.