scholarly journals Activation of SGK1 in Endometrial Epithelial Cells in Response to PI3K/AKT Inhibition Impairs Embryo Implantation

2016 ◽  
Vol 39 (5) ◽  
pp. 2077-2087 ◽  
Author(s):  
Madhuri S. Salker ◽  
Jennifer H. Steel ◽  
Zohreh Hosseinzadeh ◽  
Jaya Nautiyal ◽  
Zoe Webster ◽  
...  

Background: Serum & Glucocorticoid Regulated Kinase 1 (SGK1) plays a fundamental role in ion and solute transport processes in epithelia. In the endometrium, down-regulation of SGK1 during the window of receptivity facilitates embryo implantation whereas expression of a constitutively active mutant in the murine uterus blocks implantation. Methods/Results: Here, we report that treatment of endometrial epithelial cells with specific inhibitors of the phosphoinositide 3-kinase (PI3K)/AKT activity pathway results in reciprocal activation of SGK1. Flushing of the uterine lumen of mice with a cell permeable, substrate competitive phosphatidylinositol analogue that inhibits AKT activation (AKT inhibitor III) resulted in Sgk1 phosphorylation, down-regulation of the E3 ubiquitin-protein ligase Nedd4-2, and increased expression of epithelial Na+ channels (ENaC). Furthermore, exposure of the uterine lumen to AKT inhibitor III prior to embryo transfer induced a spectrum of early pregnancy defects, ranging from implantation failure to aberrant spacing of implantation sites. Conclusion: Taken together, our data indicate that the balanced activities of two related serine/threonine kinases, AKT and SGK1, critically govern the implantation process.

Author(s):  
Chia-Hung Chou ◽  
Shee-Uan Chen ◽  
Chin-Der Chen ◽  
Chia-Tung Shun ◽  
Wen-Fen Wen ◽  
...  

Abstract Context A supraphysiological estradiol (E2) concentration after ovarian stimulation is known to result in lower embryo implantation rates in in vitro fertilization (IVF). Endometrial epithelial cells (EECs) apoptosis occurs after the stimulation with high E2 concentrations, and mitochondria play important roles in cell apoptosis. Objective To investigate the mitochondrial function in EECs after the stimulation with high E2 concentrations. Materials and Methods Human EECs were purified and cultured with different E2 concentrations (10-10, 10-9, 10-8, 10-7 M) in vitro, in which 10-7 M is supraphysiologically high. Eight-week-old female mouse endometrium was obtained 5.5 days after the injection of 1.25 IU or 20 IU equine chorionic gonadotropin (eCG), roughly during the embryo implantation window, to examine the in vivo effects of high E2 concentrations on mouse EECs. Results In vivo and in vitro experiments demonstrated decreased mitochondrial DNA contents and ATP formation after EECs were stimulated with supraphysiologically high E2 concentrations than those stimulated with a physiologic E2 concentration. Less prominent immunofluorescence mitochondrial staining, fewer mitochondria number under electron microscopy, lower JC-1 aggregate/monomer ratio, and greater reactive oxygen species (ROS) production were found after EECs were stimulated with supraphysiologically high E2 concentrations. The high E2-induced ROS production was reduced when EECs were pretreated with N-acetyl-cysteine (NAC) in vitro, but remained unchanged after the pretreatment with coenzyme Q10. Conclusion High E2 concentrations increase extra-mitochondrial ROS production in EECs and subsequently result in mitochondrial dysfunction.


Endocrinology ◽  
2009 ◽  
Vol 150 (2) ◽  
pp. 897-905 ◽  
Author(s):  
Narayanan Krishnaswamy ◽  
Ghislain Danyod ◽  
Pierre Chapdelaine ◽  
Michel A. Fortier

Interferon-τ (IFNτ) is the embryonic signal responsible for pregnancy recognition in ruminants. The primary action of IFNτ is believed to be mediated through inhibition of prostaglandin F2α (PGF2α) released from the endometrial epithelial cells in response to oxytocin (OT). Our working hypothesis was that the antiluteolytic effect of IFNτ also involved modulation of PG production downstream of OT receptor (OTR) and/or cyclooxygenase 2 (COX2). There is currently no OT-sensitive endometrial cell line to study the molecular mechanisms underlying our hypotheses. Therefore, we established an immortalized bovine endometrial epithelial cell line (bEEL) exhibiting OT response. These cells were cytokeratin positive, expressed steroid receptors, and exhibited preferential accumulation of PGF2α over PGE2. The bEEL cells were highly sensitive to OT, showing time- and concentration-dependent increase in COX2 transcript and protein and PGF2α accumulation. Interestingly, IFNτ (20 ng/ml) significantly reduced OT-induced PGF2α accumulation, but surprisingly, the effect was not mediated through down-regulation of either OTR or COX2. Rather, IFNτ up-regulated COX2 in a time- and concentration-dependent manner while decreasing OT-induced PG accumulation. This suggests that COX2 is not a primary target for the antiluteolytic effect of IFNτ. Because IFNτ reduced OT-stimulated PGF2α accumulation within 3 h, the mechanism likely involves a direct interference at the level of the OT signaling or transcription in addition to the down-regulation of OTR observed in vivo. In summary, bEEL cells offer a unique in vitro model for investigating the cellular and molecular mechanisms underlying OT and IFNτ response in relation with luteolysis and recognition of pregnancy in the bovine. Interferon-τ acts as a competitive partial agonist, stimulating basal but inhibiting oxytocin- and phorbol myristate acetate-stimulated prostaglandin F2α production in immortalized bovine endometrial epithelial cells.


2020 ◽  
Vol 26 (11) ◽  
pp. 825-836
Author(s):  
Bing Wang ◽  
Yan Shao

Abstract We previously showed that annexin A2 (Axna2) was transiently expressed at the embryo-uterine luminal epithelium interface during the window of implantation and was involved in mouse embryo implantation. At the same time, Axna2 was reported to be upregulated in human receptive endometrium, which was critical for embryo attachment as an intracellular molecule. Here, we identified Axna2 as a membrane-bound molecule on human endometrial epithelial cells and trophoblast cells, and the outer surface membrane-bound Axna2 was involved in human embryo attachment. In addition, physiological levels of estrogen and progesterone increased the expression of overall Axna2 as well as that in the extracellular surface membrane protein fraction in human endometrial cells. Furthermore, p11 (or S100A10, a member of the S100 EF-hand family protein, molecular weight 11 kDa) was involved in the translocation of Axna2 to the outer surface membrane of endometrial epithelial cells without affecting its overall expression. Finally, the surface relocation of Axna2 was also dependent on cell–cell contact and calcium binding. A better understanding of the function and regulation of Axna2 in human endometrium may help us to identify a potential therapeutic target for subfertile and infertile patients.


2009 ◽  
Vol 21 (9) ◽  
pp. 128
Author(s):  
G. Nie ◽  
Y. Li ◽  
L. A. Salamonsen ◽  
C. Simon ◽  
A. Quiñonero ◽  
...  

Successful embryo implantation is an important step in establishing pregnancy, requiring a healthy embryo and a receptive endometrium. Establishment of endometrial receptivity involves morphological and physiological changes initially in the endometrial epithelium, but the underlying molecular mechanisms are not fully understood. We have previously demonstrated that proprotein convertase 5/6 (PC6), a member of the proprotein convertase (PC) family, is up-regulated in the endometrium specifically at implantation in association with epithelial differentiation, in the human and monkey. PCs convert a range of precursor proteins of important functions into their bioactive forms; they are thus regarded as critical “master switch” molecules. The present study aimed to determine whether PC6 is a critical regulator in the endometrial epithelium for receptivity and implantation. We examined whether endometrial epithelial PC6 dys-regulation is associated with implantation failure in women and whether knockdown of PC6 by siRNA in human endometrial epithelial cells affects embryo adhesion in a cell culture model. Endometrial PC6 expression was assessed by immunohistochemistry in the mid-secretory phase of the menstrual cycle (receptive phase) in two unique clinical cohorts comprising women of known fertility and infertility (with no obvious gynecological disorders, and with fertile males). Endometrial epithelial PC6 levels were significantly lower in infertile vs fertile women in both cohorts. To further establish that PC6 is important for receptivity, a cell model relevant to human implantation was used involving co-culture of uterine epithelial cells with mouse embryos. The epithelial cells were stably transfected with PC6 siRNA and PC6 knock down was confirmed at the levels of mRNA, protein, and activity by real-time RT-PCR, Western blotting and activity assay respectively. Embryos readily adhered to normal epithelial cells, but the adhesion was significantly reduced in the PC6 knockdown epithelial cells. We are currently using proteomics technology to identify the pathways affected by PC6 knockdown. These results strongly suggest that PC6 plays a critical role in modulating the human endometrial epithelium for receptivity and implantation.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sophie Kinnear ◽  
Lois A. Salamonsen ◽  
Mathias Francois ◽  
Vincent Harley ◽  
Jemma Evans

Abstract The yin and yang of female fertility is a complicated issue; large numbers of women/couples desire fertility and seek assisted reproduction intervention to achieve conception, while others seek to prevent pregnancy. Understanding specific molecules which control endometrial-embryo interactions is essential for both facilitating and preventing pregnancy. SOX17 has recently emerged as an important transcription factor involved in endometrial receptivity and embryo implantation. However, studies to date have examined mouse models of pregnancy which do not necessarily translate to the human. Demonstration of a role for ‘implantation factors’ in a human system is critical to provide a rationale for in depth clinical investigation and targeting of such factors. We demonstrate that SOX17is present within the receptive human endometrium and is up-regulated within human endometrial epithelial cells by combined estrogen & progesterone, the hormonal milieu during the receptive window. SOX17 localizes to the point of adhesive contact between human endometrial epithelial cells and a human ‘embryo mimic’ model (trophectodermal spheroid). Targeting SOX17 in endometrial epithelial cells using CRISPR/Cas9 knockdown or a SOX-F family inhibitor, MCC177, significantly inhibited adhesion of an trophectodermal spheroids to the epithelial cells thereby preventing ‘implantation’. These data confirm the important role of endometrial SOX17 in human endometrial receptivity and embryo implantation.


2022 ◽  
Vol 20 (1) ◽  
Author(s):  
Marina Segura-Benítez ◽  
María Cristina Carbajo-García ◽  
Ana Corachán ◽  
Amparo Faus ◽  
Antonio Pellicer ◽  
...  

Abstract Background Successful implantation is dependent on coordination between maternal endometrium and embryo, and the role of EVs in the required cross-talk cell-to-cell has been recently established. In this regard, it has been reported that EVs secreted by the maternal endometrium can be internalized by human trophoblastic cells transferring their contents and enhancing their adhesive and invasive capacity. This is the first study to comprehensively evaluate three EV isolation methods on human endometrial epithelial cells in culture and to describe the proteomic content of EVs secreted by pHEECs from fertile women. Methods Ishikawa cells and pHEECs were in vitro cultured and hormonally treated; subsequently, conditioned medium was collected and EVs isolated. Ishikawa cells were used for the comparison of EVs isolation methods ultracentrifugation, ExoQuick-TC and Norgen Cell Culture Media Exosome Purification Kit (n = 3 replicates/isolation method). pHEECs were isolated from endometrial biopsies (n = 8/replicate; 3 replicates) collected from healthy oocyte donors with confirmed fertility, and protein content of EVs isolated by the most efficient methodology was analysed using liquid chromatography–tandem mass spectrometry. EV concentration and size were analyzed by nanoparticle tracking analysis, EV morphology visualized by transmission electron microscopy and protein marker expression was determined by Western blotting. Results Ultracentrifugation was the most efficient methodology for EV isolation from medium of endometrial epithelial cells. EVs secreted by pHEECs and isolated by ultracentrifugation were heterogeneous in size and expressed EV protein markers HSP70, TSG101, CD9, and CD81. Proteomic analysis identified 218 proteins contained in these EVs enriched in biological processes involved in embryo implantation, including cell adhesion, differentiation, communication, migration, extracellular matrix organization, vasculature development, and reproductive processes. From these proteins, 82 were selected based on their functional relevance in implantation success as possible implantation biomarkers. Conclusions EV protein cargos are implicated in biological processes related to endometrial receptivity, embryo implantation, and early embryo development, supporting the concept of a communication system between the embryo and the maternal endometrium via EVs. Identified proteins may define new biomarkers of endometrial receptivity and implantation success.


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