Expression Of Kras In The Endometrium Of Early Pregnant Mice And Its Effect During Embryo Implantation

Objective:Successful embryo implantation requires a functionally normal blastocyst and a receptive endometrium. During this period, to prepare for receptivity, the uterus undergoes a series of physiological processes. KRAS, as an oncogene, has been found to participate in regulating processes such as cell proliferation, differentiation, apoptosis and survival. To investigate the role of KRAS in the process of embryo implantation, real-time fluorescence quantitative PCR, immunohistochemistry and Western blot were used to detect the expression of KRAS mRNA and protein in the endometrium of pseudopregnant and early pregnant mouse. Induction of artificial decidualization in vivo and in vitro was used to explore role of KRAS in endometrium decidual process. Transfecting KRAS siRNA in vitro was performed to investigate the role of KRAS in regulating the proliferation of stromal cells. Finally, the role of KRAS in regulating embryo implantation was confirmed by injection of uterine horn with KRAS siRNA. It would provide a foundation for further experimental studies on mechanisms associated with embryo implantation.Methods:(1) Investigating the expression of KRAS mRNA and protein in the endometrium of pseudopregnant and early pregnant mouse by real-time fluorescence quantitative PCR, immunohistochemistry and Western blot.(2) Induction of artificial decidualization in vivo and in vitro was used to explore role of KRAS in endometrium decidual process.(3) Prolactin (PRL) secretion levels in cell culture after transfection with KRAS siRNA and induction of artificial decidualization in vitro were detected by ELISA.(4) Cell cycle analysis was performed by Flow Cytometry after transfection with KRAS siRNA.(5) The number of implantation sites was counted after injection of the uterine horn with KRAS siRNA. The implantation sites were identified by intravenous injection of Chicago blue through tail vein.Results:(1) There was no significant difference in the KRAS mRNA and protein expression level in the endometrium of pregnant mice.(2) The results of immunohistochemistry analysis showed that the KRAS expression location in the endometrium changed with pregnancy progress. The KRAS mainly expressed in the luminal and glandular epithelium on day 1,4,5 and 6 of pregnancy and increased gradually. On day 6 and 7 implantation sites of pregnancy, KRAS mainly expressed in the primary decidual zone and expanded.(3) KRAS regulates endometrium decidual process and the proliferation of stromal cells.(4) KRAS plays an important role in the process of embryo implantation.Conclusion:KRAS can regulate endometrium decidual process and proliferation of stromal cells by changes of KRAS expression location and then affects the process of embryo implantation of mice.