Down-regulation of K+ ion channel coding gene (KCNQ1) in endometrium of women with recurrent implantation failure

Background: Endometrium is receptive to the embryo only during a defined period in the menstrual cycle called the window of implantation. Pattern of genes expression leads to receptive or non-receptive endometrium, in this phase. Many ion channels were found to be involved in this process. It was demonstrated that the relatively high concentration of K+ in intrauterine fluid is required for the viability and fertilizing capacity of spermatozoa. Therefore, K+ concentration in uterine cavity and K+ activity in endometrium have major role in embryo implantation. KCNQ1 gene encodes a voltage-gated potassium channel in epithelium of many organs such as endometrium and is hypothesized that have functional role in implantation. The aim of this study was to compare expression of KCNQ1 in endometrium of RIF patients vs. fertile women.Methods: Endometrial samples obtained from 22-35 year old women through window of implantation by pipelle including 20 infertile patients with recurrent implantation failure (RIF) and 9 volunteer fertile donors, one cycle before ovarian stimulation as control group. Expression of KCNQ1 in endometrial samples of fertile and RIF women were evaluated quantitatively by real-time PCR. Data were analyzed by Independent-Samples T test followed by Tukey’s test using SPSS version 22 software.Result: The data showed a significant decrease in mRNA expression of KCNQ1 gene in endometrium of RIF patients vs. fertile group. (pValue≤0.01)Conclusion: These data revealed association between the gene expression of ion channels and embryo implantation and suggest the low density of K+ may enhance the cleavage rate of preimplantation embryos.