Expression And Function Of Cyclophilin A(CyPA)During Mouse Implantation

Embryo implantation,also known as embryo nidation,is a process in which the blastocyst in the activated state interacts with the uterus in the receptive state,resulting in the formation of a close relationship between the trophoblast and the endometrium.The process of embryo implantation is divided into three stages: localization,adhesion and invasion.Estrogen(E2)and progesterone(P4)play an important role in the process of embryo implantation.Under the regulation of estrogen and progesterone,many molecules and signaling pathways are activated by spatiotemporal specificity and establish embryo –uterine dialogue.Failure of embryo implantation directly leads to pregnancy failure and infertility.Cyclophilin A(Cy PA)is a member of immunocyclophilic proteins family with the activity of peptide-proline cistrans isomerase(PPIase),which regulates protein folding and translocation by catalyzing proline residues in specific sequences of target proteins.Stimulated by radiation,infection and oxidative stress,Cy PA protein in the cytoplasm can also be secreted to the extracellular environment.By interacting with Cy PA receptor CD147 on the cell surface,extracellular Cy PA regulates many physiological processes by autocrine and paracrine means,such as regulating cell apoptosis,promoting cell migration,matrix degradation and ROS(reactive oxygen species,ROS)generation.Although the role of CD147 in embryo implantation has been reported in literatures,whether Cy PA regulates embryo implantation has not been reported in literatures.In pregnancy mice model this paper to explore Cy PA in mice of the expression and function of the uterus.Firstly we use of in situ hybridization method to detect the Cy PA m RNA expression in early pregnancy in mice.The results showed that 1-2 days early pregnancy in mice,Cy PA m RNA in uterine epithelium and glandular epithelium with strong expression,in 3-4 days,Cy PA m RNA in addition to outside the uterine epithelium and glandular epithelium on the expression,also expression in endometrial stromal cells.After implantation on day 5,Cy PA was largely expressed in the stromal cells located around the embryo at the implantation site,but only weakly in the stromal cells at the inter-implantation site at day 5.With the progress of gestation,there were abundant expressions in the secondary decidual area on the 6?8th day of pregnant.At the same time,we used immunofluorescence assay to detect the expression location of Cy PA protein in the uterus of early pregnancy of mice.During the 1-5 days of pregnant,the expression of Cy PA protein is similar to m RNA.However,during the 6th to 8th day of pregnant,the expression of Cy PA protein tends to have strong immune signals in the deep undifferentiated stromal cells close to the muscle layer.In addition,strong signals were also found near the embryo on the 7-8 day of pregnant.In ovariectomized mice,Cy PA was highly sensitive to estrogen stimulation and showed a time dependence,peaking at 12 hours.Mice were injected with Cy PA-specific inhibitor TMN355 on the third and fourth day of pregnancy for two consecutive days,which could significantly reduce the embryo implantation site.At the same time,in vitro cultured primary mouse uterine stromal cells,the use of specific inhibitors and si RNA interference methods,confirmed that Cy PA can activate Stat3(signal transducer and activator of transcription 3,Stat3)activity,but also can up-regulate CD147,MMP3,MMP9.In conclusion,Cy PA may play an important role in embryo implantation.