Effects Of CYTL1 On Regulation Of Embryo Implantation

Implantation involves a complex sequence of signaling events from the acquisition of adhesion ligands together with secretion of important components that are crucial to the establishment of pregnancy. In the network of the complex interaction between maternal uterine and embryo,under the influence of ovarian hormones, plenty of signaling component execute important effect during the period of embryo implantation, including adhesion molecules and cytokine, growth factor and others.Cytokine-like 1 (CYTL1), also called C17, UNQ1942/PRO4425,was first identified as an secreted protein majorly expressed in the bone marrow and cord blood mononuclear cells that bear the CD34 surface marker, whereas not in CD34 negative cells, meanwhile CYTL1 gene increases in benign prostatic hypertrophy, Recent researches have report that function in the cartilage development, and the following researches focus on its role in maintaining cartilage homeostasis by functioning as an regulation cytokine. Recent reports have suggested that CYTL1 is more likely to adopt a CCL2-like chemokine folding structure to signal through the CCR2 receptor and might serve as an important regulation factor. However there is no reports that concerning the relationship between CYTL1 and embryo implantation.Objective:Our aim is to figure out the expression and regulation of CYTL1 in the stages of early-pregnancy especially in embryo implantation in the research of early-pregnancy mice and related cell-lines in vitro.Methods:(1)Through the establishment of early-pregnancy mice, RT-PCR was to determine the expression of endometrial CYTL1 in the different stages of early-pregnancy.(2) Real-time PCR, RT-PCR were applied to detect the expression of CYTL1 in different cell-lines.(3) RT-PCR,ELISA were applied to determine the effects of progesterone and estradiol on the CYTL1 expression in endometrial cell. (4)CCK-8 was applied to determine the effect of CYTL1 on the proliferation of endometrial cell. (4)The regulation of CYTL1 on LIF, HBEGF, CD82 expression in endometrial cells was determined by RT-PCR adn ELISA. (5)hrough the establishment of embryo implantation model in vitro, JAR adhesive rate to endometrial cell was analyzed to determine the effect of CYTL1 on cell adhesion ability.Results:(1)The analysis by RT-PCR reveals that the level of CYTL1 expression was significantly increased during the period of embryo implantation while in the none-pregnancy and pre-implantation-period mice, the CYTL1 is not strongly expressed in endometrium. (2)CYTL1 mRNA is identified to be expressed in endometrial cell line HEC-1-A and RL95-2, but not trophoblastic cell; meanwhile,the level of CYTLl expression in HEC-1-A is significantly higher than that of RL95-2; (3) The effect of progesterone and estradiol on CYTL1 expression reveals that progesterone and estradiol significantly enhances the CYTL1 mRNA and protein expression. (4) The proliferation of endometrial HEC-1-A and RL95-2 cell was significantly enhanced by the application of CYTL1.(5) The level of LIF,HB-EGF,CD82 mRNA and protein expressed in HCA-1-A and RL95-2 are significantly increased by the application of CYTLl. (6) In Ihe embryo implantation in vitro model, the rate of JAR cell adhesive to endometrial cell is significantly increase by the application of CYTL1.Conclusions:(1) The uterine endometrium displays maximal level of CYTLl expression in the stage of embryo implantation in early-pregnancy in mice, at the same time, the level of CYTL1 is strongly expressed in HEC-1-A compared with RL952, which is coherent with those signaling mediator related to embryo implantation like LIF,HB-EGF. (2) The expression of CYTL1 could be significantly enhanced in the influence of progesterone and estradiol, which function as important roles in the progress of embryo implantation, and it indicates CYTL1 could serve as a mediator in implantation,and CYTLl contribute to the establishment of pregnancy. (3) CYTL1 could execute a positive impact on the proliferation of endometrial cell which belong a key step in the process of the establishment of endometrial decidualization, and it suggests that CYTL1 could work as an active cytokine in the process of decidualization. (4)CYTL1 can significantly activate the endometrial expression of LIF,HB-EGF,C82,all of which serve as important mediator in implantation,therefore,CYTLl could work as a regulatory factor in embryo implantation. (4)The rate of JAR adhesion to endometrial cell was increase by the application of CYTL1, which means that CYTL1 could enhance the ability of adhesion in endometrial cell, therefore,CYTL1 could function in the process of embryo implantation.