156. IDENTIFICATION OF SCAFFOLDING PROTEINS AS PC6 SUBSTRATES IN THE HUMAN ENDOMETRIAL EPITHELIAL CELLS FOR EMBRYO IMPLANTATION

2010 ◽  
Vol 22 (9) ◽  
pp. 74
Author(s):  
S. Heng ◽  
Y. Li ◽  
A. N. Stephens ◽  
A. Rainczuk ◽  
G. Nie
Keyword(s):  
Epithelial Cells ◽  
Molecular Mechanisms ◽  
Embryo Implantation ◽  
Scaffolding Proteins ◽  
Proprotein Convertase ◽  
Sirna Sequence ◽  
C Terminus ◽  
Precursor Proteins ◽  
Endometrial Epithelium ◽  
Endometrial Epithelial Cells

Successful embryo implantation is an important step in establishing pregnancy, which requires a healthy embryo and a receptive endometrium. Establishment of endometrial receptivity involves morphological and physiological changes initially in the endometrial epithelium, however 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 aim of this study was to identify target proteins of PC6 in the endometrial epithelial cells important for implantation. We used a HEC1A cell line in which PC6 was stably knocked down by siRNA approach (HEC1A-PC6). HEC1A cells that were similarly transfected with a scrambled siRNA sequence (HEC1A-control) were used as the control. Previous study confirmed that HEC1A-PC6 cells had much reduced capacity to adhere to blastocyst. A proteomic comparison between HEC1A-PC6 treated with or without human recombinant PC6 identified ezrin as a potential PC6 substrate. Ezrin is a cytoplasmic protein which is known to bind to ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50) thereby translocating to the plasma membrane.This complex has been associated with cytoskeletal re-organisation and changes in cell polarity. Co-immunoprecipitation of ezrin and EBP50 showed that knockdown of PC6 allowed the binding of ezrin to the C-terminus of EBP50 in HEC1A-PC6, whereas PC6 cleavage of EBP50 in HEC1A-control prevented the binding. This was also confirmed by immunofluorescence showing that ezrin and EBP50 were co-localized to the plasma membrane in HEC1A-PC6. This study thus identified that PC6 regulates scaffolding proteins such as EBP50 and ezrin in the endometrium for embryo implantation.

529. PROPROTEIN CONVERTASE 6 PLAYS A CRITICAL ROLE IN MODULATING THE HUMAN ENDOMETRIAL EPITHELIUM FOR RECEPTIVITY AND IMPLANTATION

2009 ◽  
Vol 21 (9) ◽  
pp. 128
Author(s):  
G. Nie ◽  
Y. Li ◽  
L. A. Salamonsen ◽  
C. Simon ◽  
A. Quiñonero ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Molecular Mechanisms ◽  
Cell Model ◽  
Embryo Implantation ◽  
Critical Role ◽  
Proprotein Convertase ◽  
Gynecological Disorders ◽  
Proteomics Technology ◽  
A Cell ◽  
Endometrial Epithelium

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.

scholarly journals Modulation of endometrial E-Cadherin and N-Cadherin by ovarian steroids and embryonic stimuli

2021 ◽  
Author(s):  
Abhishek Tiwari ◽  
Nancy Ashray ◽  
Neha Singh ◽  
Shipra Sharma ◽  
Deepak N Modi
Keyword(s):  
Epithelial Cells ◽  
Epithelial To Mesenchymal Transition ◽  
Embryo Implantation ◽  
Combined Treatment ◽  
Junctional Complex ◽  
Luminal Epithelium ◽  
Mesenchymal Transition ◽  
Endometrial Epithelium ◽  
Endometrial Epithelial Cells ◽  
E Cadherin

The endometrium is a dynamic tissue that undergoes extensive remodelling to attain a receptive state which is further modulated in presence of an embryo for successful initiation of pregnancy. Cadherins are the proteins of junctional complex of which E-cadherin (E-Cad) is crucial for maintaining epithelial cell state and integrity of the epithelial barrier; gain of N-cadherin (N-Cad) in epithelial cells leads to epithelial to mesenchymal transition (EMT). In the present study, we aimed to investigate the expression of E-Cad and N-Cad in the mouse endometrial luminal epithelium and its modulation by estrogen, progesterone and embryonic stimuli. We observed that E-Cad is diffusely expressed in the luminal epithelium of mouse endometrium during the estrus stage and upon estrogen treatment. It is apico-laterally and basolaterally sorted at the diestrus stage and in response to combined treatment of estrogen and progesterone. In 3D spheroids of human endometrial epithelial cells, combined treatment with estrogen and progesterone led to lateral sorting of E-Cad. In the mouse endometrium at the time of embryo implantation, there is loss of E-Cad which was associated with the gain of N-Cad suggestive of EMT in the luminal epithelium. This EMT is possibly driven by embryonic stimuli as treatment with estrogen and progesterone did not lead to gain of N-Cad expression. In conclusion, the present study demonstrates that steroid hormones directly affect E-Cad sorting in the endometrial epithelium.

scholarly journals Trophectoderm differentiation to invasive syncytiotrophoblast is induced by endometrial epithelial cells during human embryo implantation

2020 ◽  
Author(s):  
Peter T Ruane ◽  
Terence Garner ◽  
Lydia Parsons ◽  
Phoebe A Babbington ◽  
Susan J Kimber ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Gene Networks ◽  
Embryo Implantation ◽  
Blastocyst Stage ◽  
Stage Embryo ◽  
Trophoblast Stem Cell ◽  
Endometrial Epithelium ◽  
Gene Ontologies ◽  
Endometrial Epithelial Cells ◽  
Human Implantation

AbstractAt implantation, trophoblast derived from the trophectoderm of the blastocyst-stage embryo invades the endometrium to establish pregnancy. To understand how embryos breach the endometrial epithelium, we modelled human implantation using blastocysts or trophoblast stem cell spheroids cultured with endometrial epithelial cells (EEC). Blastocyst invasion of the EEC layer was initiated by multinuclear syncytiotrophoblast. Spheroids also invaded the epithelium with syncytiotrophoblast, and EEC induced upregulation of syncytiotrophoblast markers. Modelling implantation in silico using blastocyst and EEC transcriptomes revealed gene networks that exhibited greater connectivity and organisation in trophectoderm of the polar region of the embryonic axis. However, gene ontologies and machine learning suggested that EEC drives syncytiotrophoblast differentiation in polar and mural trophectoderm. This is the first evidence for endometrial epithelium-induced trophectoderm differentiation to invasive syncytiotrophoblast as the cellular mechanism of embryonic breaching of the endometrium in humans, with implications for reproductive medicine and our understanding of human embryonic development.

525. ROLES FOR HUMAN CHORIONIC GONADOTROPHIN IN EMBRYO-ENDOMETRIAL CROSS-TALK DURING BLASTOCYST IMPLANTATION

2009 ◽  
Vol 21 (9) ◽  
pp. 124
Author(s):  
P. Paiva ◽  
K. Meehan ◽  
L. A. Salamonsen ◽  
E. Dimitriadis
Keyword(s):  
Growth Factors ◽  
Epithelial Cells ◽  
Cross Talk ◽  
Early Embryo ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Gm Csf ◽  
Blastocyst Implantation ◽  
Endometrial Epithelium ◽  
Endometrial Epithelial Cells

Emerging evidence suggests an important role for the early embryo product human chorionic gonadotrophin (hCG) in embryo-endometrial interactions critical for successful embryo implantation1. The human endometrium is also a source of hCG, with maximal expression of hCG and its receptor, hCG/LHR, in endometrial epithelial cells during the window of implantation in vivo2,3, and in primary endometrial epithelial cells (EECs)3. Implantation is tightly regulated by growth and regulatory factors produced within the embryo-endometrial microenvironment. We hypothesise that embryo/endometrial-derived hCG mediates the molecular cross talk vital for successful implantation. The main objective of this study was to investigate the effect of hCG on the production of a selected cohort of 42 cytokines and growth factors by EECs. These included those with both known and previously unidentified roles during implantation. The secretory profile of cytokines/growth factors produced by EECs was also analysed. EECs (n=8 cultures) were isolated from biopsies collected from fertile cycling women. Cells were treated without or with recombinant hCG for 48 hr and conditioned media collected for quantitative analysis using LuminexTM multiplex technology. For the first time, a secretory profile of 42 cytokines and growth factors produced by EECs was established, as was the identification of fibroblast growth factor-2 (FGF-2) secretion by human endometrial epithelium. hCG (2 IU/ml) significantly increased the production of a number factors including those with known roles during trophoblast migration and adhesion (CX3CL1; 71±31%, CXCL10; 67±24%, CCL4; 87±12%), in trophoblast differentiation (IL-1α ; 68±31%) and with unidentified roles during implantation (CCL22; 78±40%, GM-CSF; 45±16%, FGF-2; 50±25%; all p<0.05). Upregulation of the known hCG regulated proteins, VEGF and LIF, validated this study. These findings clearly support roles for the embryo/endometrium via hCG in actively contributing to the molecular cross-talk during the early stages of implantation.

scholarly journals Mitochondrial dysfunction induced by high estradiol concentrations in endometrial epithelial cells

2019 ◽  
Author(s):  
Chia-Hung Chou ◽  
Shee-Uan Chen ◽  
Chin-Der Chen ◽  
Chia-Tung Shun ◽  
Wen-Fen Wen ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Mitochondrial Dysfunction ◽  
Embryo Implantation ◽  
Ros Production ◽  
Vitro Fertilization ◽  
Equine Chorionic Gonadotropin ◽  
In Vivo Effects ◽  
Endometrial Epithelial Cells

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.

scholarly journals Molecular Cloning and Characterization of Prostaglandin (PG) Transporter in Ovine Endometrium: Role for Multiple Cell Signaling Pathways in Transport of PGF2α

Endocrinology ◽  
2007 ◽  
Vol 149 (1) ◽  
pp. 219-231 ◽  
Author(s):  
S. K. Banu ◽  
J. Lee ◽  
M. C. Satterfield ◽  
T. E. Spencer ◽  
F. W. Bazer ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Epithelial Cells ◽  
Estrous Cycle ◽  
Molecular Mechanisms ◽  
Growth Factor Receptor ◽  
Prostaglandin F2α ◽  
Cellular Transport ◽  
Endometrial Cells ◽  
Amino Terminal ◽  
Endometrial Epithelial Cells

In ruminants, endometrial prostaglandin F2α (PGF2α) is the luteolytic hormone. Cellular transport of PGF2α in the uterine endometrium is critical for regulation of the estrous cycle. Molecular mechanisms responsible for control of PGF2α transport in endometrium during luteolysis are largely unknown. In the present study, we characterized the prostaglandin transporter (PGT) in ovine endometrium. Ovine PGT cDNA consists of 1935 nucleotides that encode 644 amino acids. In ovine endometria, PGT is highly expressed during the period of luteolysis, between d 14 and 16 of the estrous cycle, in luminal and glandular epithelia. Pharmacological and genomic inhibition of PGT indicates that it is responsible for influx and efflux of PGF2α in ovine endometrial epithelial cells. Inhibition of PGT during the period of luteolysis prevents the release of oxytocin-induced PGF2α pulses, and maintains functional corpus luteum and its secretion of progesterone. In ovine endometrial epithelial cells, protein kinase A and protein kinase C pathways are involved in regulating the influx of PGF2α, whereas epidermal growth factor receptor pathways are implicated in regulation of influx and efflux of PGF2α. The ERK1/2 pathway is associated with efflux of PGF2α, whereas Jun-amino-terminal kinase/stress-activated protein kinase pathways are involved in both efflux and influx of PGF2α. Phosphatidylinositol 3-kinase pathways are not involved in either influx or efflux of PGF2α in ovine endometrial epithelial cells. These are the first results to demonstrate a functional role for PGT in regulation of PGF2α efflux and influx in ovine endometrial cells that influence luteolytic mechanisms in ruminants.

scholarly journals Oxytocin Receptor Down-Regulation Is Not Necessary for Reducing Oxytocin-Induced Prostaglandin F2α Accumulation by Interferon-τ in a Bovine Endometrial Epithelial Cell Line

Endocrinology ◽  
2009 ◽  
Vol 150 (2) ◽  
pp. 897-905 ◽  
Author(s):  
Narayanan Krishnaswamy ◽  
Ghislain Danyod ◽  
Pierre Chapdelaine ◽  
Michel A. Fortier
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Line ◽  
Molecular Mechanisms ◽  
Prostaglandin F2α ◽  
Epithelial Cell Line ◽  
Dependent Manner ◽  
Down Regulation ◽  
Endometrial Epithelial Cell ◽  
Endometrial Epithelial Cells

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.

Annexin A2 acts as an adherent molecule under the regulation of steroids during embryo implantation

2020 ◽  
Vol 26 (11) ◽  
pp. 825-836
Author(s):  
Bing Wang ◽  
Yan Shao
Keyword(s):  
Epithelial Cells ◽  
Outer Surface ◽  
Calcium Binding ◽  
Surface Membrane ◽  
Embryo Implantation ◽  
Annexin A2 ◽  
Endometrial Cells ◽  
Membrane Bound ◽  
Endometrial Epithelial Cells ◽  
Embryo Attachment

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.

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