RL95-2 Cells Research Articles

MG132-mediated Suppression of the Ubiquitin-proteasome Pathway Enhances the Sensitivity of Endometrial Cancer Cells to Cisplatin.

Tumor cell resistance to cisplatin is a common challenge in endometrial cancer chemotherapy, stemming from various mechanisms. Targeted therapies using proteasome inhibitors, such as MG132, have been investigated to enhance cisplatin sensitivity, potentially offering a novel treatment approach. The aim of this study was to investigate the effects of MG132 on cisplatin sensitivity in the human endometrial cancer (EC) cell line RL95-2, focusing on cell proliferation, apoptosis, and cell signaling. Human endometrial cancer RL95-2 cells were exposed to MG132, and cell viability was assessed in a dose-dependent manner. The study evaluated the effect of MG132 on cisplatin-induced proliferation inhibition and apoptosis, correlating with caspase-3 activation and reactive oxygen species (ROS) upregulation. Additionally, we examined the inhibition of the ubiquitin-proteasome system and the expression of pro-inflammatory cytokines IL-1β, IL-6, IL-8, and IL-13 during MG132 and cisplatin co-administration. MG132 exposure significantly reduced cell viability in a dose-dependent manner. It augmented cisplatin- induced proliferation inhibition and enhanced apoptosis, correlating with caspase-3 activation and ROS upregulation. Molecular analysis revealed a profound inhibition of the ubiquitin-proteasome system. MG132 also significantly increased the expression of cisplatin-induced pro-inflammatory cytokines, suggesting a transition from chronic to acute inflammation. MG132 enhances the therapeutic efficacy of cisplatin in human EC cells by suppressing the ubiquitin- proteasome pathway, reducing cell viability, enhancing apoptosis, and shifting the inflammatory response. These findings highlighted the potential of MG132 as an adjuvant in endometrial cancer chemotherapy. Further research is needed to explore detailed mechanisms and clinical applications of this combination therapy.

SIRT1-mediated deacetylation of FOXO3 enhances mitophagy and drives hormone resistance in endometrial cancer

BackgroundThe complex interplay between Sirtuin 1 (SIRT1) and FOXO3 in endometrial cancer (EC) remains understudied. This research aims to unravel the interactions of deacetylase SIRT1 and transcription factor FOXO3 in EC, focusing on their impact on mitophagy and hormone resistance.MethodsHigh-throughput sequencing, cell experiments, and bioinformatics tools were employed to investigate the roles and interactions of SIRT1 and FOXO3 in EC. Co-immunoprecipitation (Co-IP) assay was used to assess the interaction between SIRT1 and FOXO3 in RL95-2 cells. Functional assays were used to assess cell viability, proliferation, migration, invasion, apoptosis, and the expression of related genes and proteins. A mouse model of EC was established to evaluate tumor growth and hormone resistance under different interventions. Immunohistochemistry and TUNEL assays were used to assess protein expression and apoptosis in tumor tissues.ResultsHigh-throughput transcriptome sequencing revealed a close association between SIRT1, FOXO3, and EC development. Co-IP showed a protein–protein interaction between SIRT1 and FOXO3. Overexpression of SIRT1 enhanced FOXO3 deacetylation and activity, promoting BNIP3 transcription and PINK1/Parkin-mediated mitophagy, which in turn promoted cell proliferation, migration, invasion, and inhibited apoptosis in vitro, as well as increased tumor growth and hormone resistance in vivo. These findings highlighted SIRT1 as an upstream regulator and potential therapeutic target in EC.ConclusionThis study reveals a novel molecular mechanism underlying the functional relevance of SIRT1 in regulating mitophagy and hormone resistance through the deacetylation of FOXO3 in EC, thereby providing valuable insights for new therapeutic strategies.

Extracellular vesicles as mediators of stress response in embryo-maternal communication.

Introduction: The pivotal role of extracellular vesicles (EVs) in facilitating effective communication between the embryo and maternal cells during the preimplantation stage of pregnancy has been extensively explored. Nonetheless, inquiries persist regarding the alterations in EV cargo from endometrial cells under stress conditions and its potential to elicit specific stress responses in trophoblast cells. Thus, the aim of this study was to elucidate the involvement of EV miRNA miRNAs in transmitting stress signals from maternal cells to trophoblasts. Methods: The receptive endometrial epithelium analogue RL95-2 cells were subjected to stress induction with 200µM CoCl2 for 24h before EV isolation. JAr trophoblast spheroids, which serve as embryos, were subjected to treatment with stressed or unstressed EVs derived from RL95-2 cells for 24h. Transcriptomic alterations in the treated JAr spheroids as well as in the untreated group, as a negative control, were investigated by mRNA sequencing. Furthermore, the changes in EV miRNAs were assessed by sequencing EV samples. Results: A comprehensive analysis comparing the miRNA profiles between stressed and unstressed EVs revealed significant changes in 25 miRNAs. Furthermore, transcriptomic analysis of JAr spheroids treated with stressed RL95-2EVs versus unstressed EVs or the untreated group demonstrated 6 and 27 differentially expressed genes, respectively. Pathway enrichment analysis showed that stressed EVs induce alterations in gene expression in trophoblast cells, which is partially mediated by EV microRNAs. Discussion: Our results suggest that EVs can transfer stress signals from endometrial cells to the embryo. These discoveries shed new light on the mechanism underlying implantation failures under stress conditions. Unraveling the role of EVs in transmitting stress signals, can extend our knowledge to pave the way for targeted interventions to manage stress-related implantation failures.

Bushen Zhuyun Decoction Improves Endometrial Receptivity by Inhibiting NF-κB/NLRP3 Signaling Pathway.

Bushen Zhuyun Decoction (BSZY), a traditional Chinese herbal prescription has shown promising effects on gynecological infertility, but the mechanism for endometrial receptivity is still unclear. This study aimed to investigate the regulatory effects of BSZY on endometrial receptivity, which plays a key role in colonization of embryo, and its regulatory mechanisms associated with NF- κB/NLRP3 pathway. SD rats at reproductive age with affected endometrial receptivity was established using mifepristone (RU486), and the regulatory effects of BSZY on endometrial receptivity were evaluated by H&E staining, and changes in sex hormones by ELISA and Western blot. Moreover, human endometrial RL95-2 cells were treated with H2O2, and inflammatory cytokines in rats and RL95-2 cells were analyzed by ELISA. The activation of NF-κB/NLRP3 signaling pathway in RL95-2 cells were characterized using immunofluorescence and Western blot. Mitochondrial morphology and function in RL95-2 cells were observed by transmission electron microscope and cell mitochondrial stress test. BSZY increased uterine endometrial thickness and attenuate histopathological changes induced by RU486. BSZY can regulate endometrial estrogen receptor and progesterone receptor, and the levels of sex hormones and inflammatory cytokines in pregnant rats. BSZY-containing serum also showed strong anti-inflammatory and cytoprotective effects in vitro. In addition, BSZY-containing serum inhibited the activation of NF-κB/NLRP3 signaling pathway, and improve mitochondrial morphology and function in RL95-2 cells. BSZY can improve endometrial receptivity, potentially by improving mitochondrial morphology and function to inhibit the activation of NF-κB/NLRP3 signaling pathway in endometrial cells, thus regulate inflammation to improve endometrial receptivity.

Dynamic monitoring of the cytotoxic effects of Cousinia iconica extracts on A549 and RL95-2 cells using the xCELLigence RTCA system

Dynamic monitoring of the cytotoxic effects of Cousinia iconica extracts on A549 and RL95-2 cells using the xCELLigence RTCA system

Influence of Aldehyde Dehydrogenase Inhibition on Stemness of Endometrial Cancer Stem Cells.

Endometrial cancer is one of the most common gynaecological malignancies. Although often diagnosed at an early stage, there is a subset of patients with recurrent and metastatic disease for whom current treatments are not effective. Cancer stem cells (CSCs) play a pivotal role in triggering tumorigenesis, disease progression, recurrence, and metastasis, as high aldehyde dehydrogenase (ALDH) activity is associated with invasiveness and chemotherapy resistance. Therefore, this study aimed to evaluate the effects of ALDH inhibition in endometrial CSCs. ECC-1 and RL95-2 cells were submitted to a sphere-forming protocol to obtain endometrial CSCs. ALDH inhibition was evaluated through ALDH activity and expression, sphere-forming capacity, self-renewal, projection area, and CD133, CD44, CD24, and P53 expression. A mass spectrometry-based proteomic study was performed to determine the proteomic profile of endometrial cancer cells upon N,N-diethylaminobenzaldehyde (DEAB). DEAB reduced ALDH activity and expression, along with a significant decrease in sphere-forming capacity and projection area, with increased CD133 expression. Additionally, DEAB modulated P53 expression. Endometrial cancer cells display a distinct proteomic profile upon DEAB, sharing 75 up-regulated and 30 down-regulated proteins. In conclusion, DEAB inhibits ALDH activity and expression, influencing endometrial CSC phenotype. Furthermore, ALDH18A1, SdhA, and UBAP2L should be explored as novel molecular targets for endometrial cancer.

Mitochondrial Calcium Uniporter (MCU) that Modulates Mitochondrial Calcium Uptake and Facilitates Endometrial Cancer Progression through Interaction with VDAC1.

Although endometrial cancer represents a frequently diagnosed malignancy of the female reproductive tract, we know very little about the factors that control endometrial cancer. Our study was presented to investigate the function of MCU in endometrial tumorigenesis and the molecular mechanisms involved. A total of 94 endometrial cancer patients were recruited into our cohort. MCU and VDAC1 expression was examined in tumor and normal tissues via immunohistochemistry and immunofluorescence. Associations of MCU and VDAC1 expression with clinicopathological characteristics were evaluated. After transfection with shRNA targeting MCU or full-length MCU plasmids, clone formation, wound healing, transwell and MitoTracker Red staining were separately presented in Ishikawa and RL95-2 cells. Moreover, Western blotting or immunofluorescence was utilized to examine the expression of MCU, VDAC1, Na+/Ca2+/Li+ exchanger (NCLX), and β-catenin under VDAC1 knockdown and/or MCU overexpression or knockdown. MCU and VDAC1 expression were prominently up-regulated in endometrial cancer tissues and were significantly associated with histological grade, depth of myometrial invasion and lymph node status. MCU up-regulation enhanced clone formation, migration, and mitochondrial activity of endometrial cancer cells. The opposite results were investigated when MCU was silenced. MCU or VDAC1 silencing reduced the expression of MCU, VDAC1, NCLX, and β-catenin. Moreover, VDAC1 knockdown alleviated the promoting effect of MCU overexpression on the above proteins. This investigation demonstrated that MCU-induced mitochondrial calcium uptake plays a critical role in endometrial tumorigenesis through interaction with VDAC1.

Transcription Factor STAT3-Activated LDHB Promotes Tumor Properties of Endometrial Cancer Cells by Inducing MDH2 Expression.

The pathogenesis of endometrial cancer (EC) involves the regulation of lactate dehydrogenases. However, the role and mechanism of lactate dehydrogenase-B (LDHB) in EC progression have not been studied. The mRNA levels of LDHB and malate dehydrogenase 2 (MDH2) were detected by quantitative real-time polymerase chain reaction. Protein expression was checked by western blotting and immunohistochemistry assays. Cell proliferation, apoptosis, and invasion were analyzed by 5-Ethynyl-2'-deoxyuridine, transwell, and flow cytometry assay, respectively. Glycolysis was investigated using Glucose Assay Kit, CheKine™ Micro Lactate Assay Kit, and ADP/ATP ratio assay kit. An in vivo tumor formation assay was conducted to disclose the effect of LDHB on tumor growth in vivo. The associations among signal transducer and activator of transcription 3 (STAT3), LDHB, and MDH2 were predicted through JASPAR or GeneMANIA online database and identified by chromatin immunoprecipitation assay, dual-luciferase reporter assay, and co-immunoprecipitation assay. LDHB expression was increased in EC tissues and cells in comparison with normal endometrial tissues and human endometrial stromal cells. LDHB had the potential as a biomarker to predict the prognosis of EC patients. In addition, LDHB knockdown inhibited the proliferation, invasion, and glycolysis and promoted apoptosis of RL95-2 and Ishikawa cells. LDHB knockdown inhibited tumor property of Ishikawa cells in vivo. STAT3 bound to the promoter region of LDHB, and STAT3 silencing-induced effects were relieved after LDHB upregulation. LDHB interacted with and regulated MDH2 expression. Moreover, MDH2 overexpression rescued LDHB knockdown-induced effects on EC cell phenotypes. STAT3-activated LDHB promoted endometrial cancer cell malignancy by inducing MDH2 production.

Atractylenolide II Suppresses Glycolysis and Induces Apoptosis by Blocking the PADI3-ERK Signaling Pathway in Endometrial Cancer Cells.

Atractylenolide II (AT-II), the major bioactive compound of Atractylodes macrocephala, exhibits anti-cancer activity against many types of tumors, but the roles and the potential mechanisms in endometrial cancer remain unclear. In the present study, AT-II treatment was found to significantly suppress RL95-2 and AN3CA cell proliferation and glycolysis, and induced their apoptosis by inactivating the ERK signaling pathway, accompanied by the changing expression of the glycolytic key enzymes and apoptotic-related proteins. Peptidyl arginine deiminase 3 (PADI3), as the candidate target gene of AT-II, was highly expressed in the endometrial cancer tissues and associated with a poor prognosis according to bioinformatics analysis. PADI3 knockdown inhibited proliferation and glycolysis in endometrial cancer cells and induced cell apoptosis. Furthermore, AT-II negatively regulated the expression of PADI3, and PADI3 overexpression reversed the effects of AT-II on endometrial cancer cells. Our findings suggested that the anti-cancer function of AT-II is associated with the suppression of glycolysis and induction of apoptosis by blocking the PADI3-ERK signaling pathway. Thus, AT-II represents a novel therapeutic target for endometrial cancer and targeting AT-II may serve as a potential strategy for the clinical therapy of endometrial cancer.

#39 : Identification of Pharmacologically Active Small Molecules that Induce Spheroid Attachment and Embryo Implantation In Vitro and In Vivo

Background and Aims: Human endometrium is receptive to embryo implantation during the mid-secretory phase of the menstrual cycle. The in vitro spheroid-endometrial epithelial cells co-culture model was used in this study. We hypothesized that the small molecules from thelibrary of pharmacologically active compounds (LOPAC) can effectively enhance embryo implantation. Method: We established a high-throughput in-vitro spheroid-endometrial epithelial (BeWo-Ishikawa) cells coculture model to screen 1280 LOPAC. The top 20 small molecules which increased spheroid attachment rate were further studied in the non-receptive cell lines (HEC-1B and AN3CA). Endometrial cells were either treated with 1% DMSO (vehicle control), AZA at 20 μM (positive control) or LOPAC at 10 μM for 48 h. The trophoblastic BeWo spheroids were generated by AggreWell and the number of attached spheroids after coculture were counted. The effect on mice was studied by trans-cervical injection of LOPAC on 1.5-day postcoital (dpc) and the number of implantation sites on 5.5 dpc were evaluated. Results: Screening of 1280 LOPAC identified 255 molecules increased, and 173 molecules significantly decreased the spheroid attachment rate. The top 20 potential molecules were further studied and three of them were found to significantly increase spheroid attachment in the HEC-1B cells. Another molecule J was found to suppress spheroid attachment in receptive Ishikawa and RL95-2 cells while increase spheroid attachment significantly in non-receptive HEC-1B and AN3CA cells. In mice, molecule J could significantly increase the number of implantation sites on the treated sides when compared with non-treated sides. Conclusion: Three molecules were found to increase spheroid attachment in receptive Ishikawa cells and non-receptive HEC-1B cells. Another molecule J can increase the spheroid attachment in non-receptive HEC-1B and AN3CA cells and increase embryo implantation in ICR mice. [This study is partially supported by the GRF grants 15162211 and 17120720 to KFL]

#136 : Osteopontin Facilitates Embryo Growth, Implantation, and Cellular Metabolism via Interacting with αvβ3 and RGS2 Pathway: Evidence from Mouse Embryos and a 3D In-Vitro Implantation Model

Background and Aims: We conducted a study on mice to investigate how osteopontin, a mediator of cell-cell and cell-extracellular matrix (ECM) communication and invasion, influences embryonic development, metabolism, and implantation potential, with confirmation by a 3D in-vitro implantation model. Method: Embryos were collected from female mice and cultured under different conditions: HTF only, HTF supplemented with OPN at different doses, and OPN-supplemented HTF with anti-[Formula: see text]v[Formula: see text]3 Ab or RGS2 inhibitors. Embryo morphology, development, and implantation rates were evaluated. Microarrays were used to evaluate gene expression profiling. Choriocarcinoma JAR and epithelial RL95-2 cell lines were adopted for the in-vitro implantation model. Oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) were used to measure cellular metabolism levels. Results: The supplementation of OPN best enhanced the rate of embryo hatching-out and implantation onto the matrigel at 100 nM, but a higher degeneration rate was seen at a higher concentration ([Formula: see text]200 nM). In OPN-treated embryos, microarray analysis showed 51 significantly down-regulated genes and 60 up-regulated genes, including RGS2. Inhibition of [Formula: see text]v[Formula: see text]3 integrin decreased embryo implantation rates and down-regulated RGS2. Validation of the 3D implantation model using JAR spheroids and RL95-2 monolayer showed a similar effect. OPN also increased OCR and ECAR of the JAR cells, and migration assays revealed increased migration ability in OPN-overexpressed JAR cells, which was then inhibited by [Formula: see text]v[Formula: see text]3 and RGS2 inhibitors. Conclusion: Osteopontin, at a reasonable concentration, could enhance embryo development and implantation by interacting with [Formula: see text]v[Formula: see text]3 integrin, subsequently facilitating the RGS2 pathway. OPN has the potential to be a supplement during in vitro embryo culture in ART intervention.

Fer-mediated activation of the Ras-MAPK signaling pathway drives the proliferation, migration, and invasion of endometrial carcinoma cells.

The role of Feline sarcoma-related protein (Fer) in various cancers has been extensively studied, but its specific involvement and underlying mechanisms in the progression of endometrial carcinoma (EC) are yet to be fully understood. The expression levels of Fer were assessed in EC tissues and cell lines using real-time quantitative PCR and western blot analysis. CCK-8 assay, Edu staining, transwell assays, and flow cytometry, were conducted to evaluate the impact of Fer on EC cells. Furthermore, a mice xenograft model and immunohistochemistry (IHC) staining were utilized for in vivo analysis. The levels of Ras, pMek1/2, and pErk1/2 were determined by western blot assay. Ras-MAPK signaling pathway inhibitor was utilized to study the regulatory role of Fer on EC cells. Our findings revealed that Fer exhibited upregulation in both EC tissues and cell lines, concomitant with the activation of the Ras-MAPK signaling pathway. Silencing of Fer resulted in the suppression of cell proliferation, migration, invasion, and Ras-MAPK signaling pathway, while promoted hypoxia-induced apoptosis in RL95-2 and KLE cells. Fer overexpression stimulated cell proliferation, migration, invasion, and Ras-MAPK signaling pathway in Ishikawa and AN3-CA cells, which were reversed after treatment with either Ras or MAPK inhibitor. Moreover, silencing of Fer suppressed tumor growth and downregulated the expression of Ki-67, Ras, pMek1/2, and pErk1/2, but had no significant effect on Mek1/2 and Erk1/2, while upregulated caspase-3 expression in vivo. In summary, the upregulation of Fer in EC cells resulted in the enhancement of cell proliferation, migration, and invasion through the activation of the Ras-MAPK signaling pathway.

Low-Density Lipoprotein Contributes to Endometrial Carcinoma Cell Proliferation, Migration, and Invasion by Activating the JAK-STAT Signaling Pathway.

Cholesterol-rich low-density lipoprotein (LDL) particles have been demonstrated to regulate breast cancer cell proliferation and migration, but their biological function and relevant mechanisms in endometrial carcinoma (EC) remain unclear. Serum and tissue samples were collected from EC patients (n = 50) and patients with benign endometrial hyperplasia (n = 50). Ishikawa and RL95-2 cells were stimulated with different concentrations of LDL, followed by treatment with a JAK2 inhibitor (SD-1029). LDL concentrations were determined by ELISA. The in vitro biological behavior of cells was examined using the CCK-8 assay, EdU staining, and Transwell assay. The tumorigenicity of LDL in vivo was examined using a xenograft mouse model. western blotting, immunofluorescence, and immunohistochemistry studies were performed to measure related protein expression. The LDL concentrations and levels of p-JAK2 and p-STAT3 expression were elevated in the clinical samples. Similar trends in expression were detected in EC cells after LDL stimulation. LDL treatment significantly promoted EC cell proliferation, migration, and invasion, and also upregulated p-JAK2 and p-STAT3 expression in a dose-dependent manner. Moreover, SD-1029 dramatically blocked the LDL-mediated effects on EC cells. Intravenous injection of LDLs promoted tumor growth in the xenograft nude mice, and also increased p-JAK2, p-STAT3, and Ki-67 expression, and downregulated caspase-3 expression. These findings indicate that LDLs exert an oncogenic effect in EC cells by activating the JAK/STAT signaling pathway, and also suggest the JAK/STAT pathway as a possible therapeutic target for EC.

Exosomal miR-205-5p Improves Endometrial Receptivity by Upregulating E-Cadherin Expression through ZEB1 Inhibition.

Endometrial receptivity is a complex process that prepares the uterine endometrium for embryo implantation; insufficient endometrial receptivity is one of the causes of implantation failure. Here, we analyzed the microRNA expression profiles of exosomes derived from both receptive (RL95-2) and non-receptive (AN3-CA) endometrial epithelial cell (EEC) lines to identify exosomal miRNAs closely linked to endometrial receptivity. Among the 466 differentially expressed miRNAs, miR-205-5p was the most highly expressed in exosomes secreted from receptive RL95-2 cells. miR-205-5p, enriched at the adhesive junction, was closely related to endometrial receptivity. ZEB1, a transcriptional repressor of E-cadherin associated with endometrial receptivity, was identified as a direct target of miR-205-5p. miR-205-5p expression was significantly lower in the endometrial tissues of infertile women than in that of non-infertile women. In vivo, miR-205-5p expression was upregulated in the post-ovulatory phase, and its inhibitor reduced embryo implantation. Furthermore, administration of genetically modified exosomes overexpressing miR-205-5p mimics upregulated E-cadherin expression by targeting ZEB1 and improved spheroid attachment of non-receptive AN3-CA cells. These results suggest that the miR-205-5p/ZEB1/E-cadherin axis plays an important role in regulating endometrial receptivity. Thus, the use of exosomes harboring miR-205-5p mimics can be considered a potential therapeutic approach for improving embryo implantation.

MiR-196a-5p facilitates progression of estrogen-dependent endometrial cancer by regulating FOXO1.

Estrogen-dependent endometrial cancer mainly occurs in younger pre-menopausal and post-menopausal women and threatens their health. Recently, microRNAs (miRNAs) have been considered as novel targets in endometrial cancer treatment. Therefore, we aimed to explore the effect of miRNA (miR)-196a-5p in estrogen-dependent endometrial cancer. 17β-estradiol (E2; 2.5, 5, 10 and 20 nM) was used to treat RL95-2, HEC-1B and ECC-1 cells followed by cell viability assessment using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The level of miR-196a-5p was measured by reverse transcription-quantitative PCR (RT-qPCR). We then transfected miR-196a-5p mimic/inhibitor and Forkhead box protein O1 (FOXO1) small interfering RNA (siRNA) into E2-treated cells. Apoptotic cells were measured by flow cytometry. Wound healing and Transwell assays were implemented to assess migration and invasion. Bioinformatics and luciferase reporter assays were applied to confirm the interaction between miR-196a-5p and FOXO1. Immunoblotting determined the levels of FOXO1, Bcl-2, Bax, Caspase 3. E2 promoted cell viability and miR-196a-5p expression in RL95-2 and ECC-1 cells. miR-196a-5p mimic enhanced cell viability, migration and invasion but suppressed apoptosis and FOXO1, whilst miR-196a-5p inhibitor blocked these processes. In addition, miR-196a-5p upregulated Bcl-2, but down regulated Bax and Caspase 3 expression, an effect that was reversed by miR-196a-5p inhibitor. We determined that miR-196a-5p targeted FOXO1, and that si-FOXO1 blocked the effects of miR-196a-5p inhibitor on viability, apoptosis, migration and invasion of E2-treated RL95-2 and ECC-1 cells. Our findings suggested potential diagnostic and therapeutic applications for miR-196a-5p and its FOXO1 target in patients suffering from estrogen-dependent endometrial cancer.

Secretory Proteomic Responses of Endometrial Epithelial Cells to Trophoblast-Derived Extracellular Vesicles.

Synchronized crosstalk between the embryo and endometrium during the periconception period is integral to pregnancy establishment. Increasing evidence suggests that the exchange of extracellular vesicles (EVs) of both embryonic and endometrial origin is a critical component of embryo-maternal communication during peri-implantation. Here, we investigated whether embryonic signals in the form of EVs can modulate the endometrial epithelial cell secretome. Receptive endometrial analog RL95-2 cells were supplemented with trophoblast analog JAr cell-derived EVs, and the secretory protein changes occurring in the RL95-2 cells were analyzed using mass spectrometry. EVs of non-trophoblastic origin (HEK 293 cells) were used as the control EV source to supplement endometrial cells. Trophoblast cell-derived EVs enriched endometrial epithelial cell secretions with proteins that support embryo development, attachment, or implantation, whereas control EVs were unable to induce the same effect. The present study suggests that embryonic signals in the form of EVs may prime receptive endometrial epithelial cells to enrich their secretory proteome with critical proteomic molecules with functional importance for periconception milieu formation.

Rhythm of the First Language: Dynamics of Extracellular Vesicle-Based Embryo-Maternal Communication in the Pre-Implantation Microenvironment.

One of the most critical steps in mammalian reproduction is implantation. Embryos with an impaired capacity for embryo-maternal crosstalk are thought to have a reduced potential for implantation. One agent of embryo-maternal communication is extracellular vesicles (EV). EVs are lipid bilayer-bound biological nanoparticles implicated in intercellular communication between many of the known cell types. In the current study, we isolated EVs from trophoblast analogue JAr spheroids and supplemented the EVs with receptive endometrium analogue RL95-2 cells to simulate pre-implantation embryo-maternal dialogue. The transcriptome of the endometrial cells was examined at 30 min, 4 h and 48 h intervals using Oxford Nanopore® technology. At the time points, 30 min, 4 h and 48 h, the endometrial cells showed a significantly altered transcriptome. It seems trophoblast EVs induce a swift and drastic effect on the endometrial transcriptome. The effect peaks at around 4 h of EV supplementation, indicating a generalized effect on cell physiology. Alterations are especially apparent in biological pathways critical to embryonic implantation, such as extracellular matrix-receptor interactions and cytokine-receptor interactions. These observations can be helpful in elucidating the dynamics of embryo-maternal communication in the pre-implantation period.

Adverse effect of assisted reproductive technology-related hyperoestrogensim on the secretion and absorption of uterine fluid in superovulating mice during the peri-implantation period.

This study aimed to investigate the potential mechanism of hyperoestrogensim elicited by ovulation induction affects endometrial receptivity and leads to embryo implantation abnormality or failure. Establishment of ovulation induction mouse model. Changes in mouse body weight, ovarian weight, serum E2 level and oestrous cycle were observed. During the peri-implantation period, morphological changes in the mouse uterus and implantation sites and the localization and protein levels of oestrogen receptors ERα and ERβ, the tight junction factors CLDN3 and OCLN, the aquaporins AQP3, AQP4 and AQP8, and the sodium channel proteins SCNN1α, SCNN1β and SCNN1γ were observed. The expression and cellular localization of ERα, CLDN3, AQP8 and SCNN1 β in RL95-2 cell line were also detected by western blotting and immunofluorescence. Ovarian and body weights were significantly higher in the 5 IU and 10 IU groups than in the CON group. The E2 level was significantly higher in the 10 IU group than in the CON group. The mice in the 10 IU group had a disordered oestrous cycle and were in oestrus for a long time. At 5.5 dpc, significantly fewer implantation sites were observed in the 10 IU group than in the CON (p<0.001) and 5 IU (p<0.05) groups. The probability of abnormal implantation and abortion was higher in the 10 IU group than in the CON and 5 IU groups. CLDN3, OCLN, AQP8 and SCNN1β in the mouse endometrium were localized on the luminal epithelium and glandular epithelium and expression levels were lower in the 10 IU group than in the CON group. The protein expression level of ERα was increased by 50% in the 10 IU group compared to the CON group. The expressions of CLDN3, AQP8, SCNN1β in RL95-2 cell line were significantly depressed by the superphysiological E2, ERα agonist or ERβ agonist, which could be reversed by the oestrogen receptor antagonist. ART-induced hyperoestrogenism reduces CLDN3, AQP8 and SCNN1β expression through ERα, thereby destroying tight junctions and water and sodium channels in the endometrial cavity epithelium, which may cause abnormal implantation due to abnormal uterine fluid secretion and absorption.

The Extracellular Vesicles Proteome of Endometrial Cells Simulating the Receptive Menstrual Phase Differs from That of Endometrial Cells Simulating the Non-Receptive Menstrual Phase.

Successful embryo implantation into a receptive endometrium requires mutual endometrial-embryo communication. Recently, the function of extracellular vehicles (EVs) in cell-to-cell interaction in embryo-maternal interactions has been investigated. We explored isolated endometrial-derived EVs, using RL95-2 cells as a model of a receptive endometrium, influenced by the menstrual cycle hormones estrogen (E2; proliferative phase), progesterone (P4; secretory phase), and estrogen plus progesterone (E2P4; the receptive phase). EV sized particles were isolated by differential centrifugation and size exclusion chromatography. Nanoparticle tracking analysis was used to examine the different concentrations and sizes of particles and EV proteomic analysis was performed using shotgun label-free mass spectrometry. Our results showed that although endometrial derived EVs were secreted in numbers independent of hormonal stimulation, EV sizes were statistically modified by it. Proteomics analysis showed that hormone treatment changes affect the endometrial EV's proteome, with proteins enhanced within the EV E2P4 group shown to be involved in different processes, such as embryo implantation, endometrial receptivity, and embryo development, supporting the concept of a communication system between the embryo and the maternal endometrium via EVs.

Sialyl Lewis X mediates interleukin-1 beta-induced trophoblast adhesion to endometrial cells during human embryo implantation.

Cell surface carbohydrate antigens sialyl Lewis X (sLeX) and Lewis Y (LeY) are paramount glycoconjugates and are abundantly expressed in the receptive endometrium. Furthermore, among the important biological functions of both antigens is their role in leukocytes adhesion and extravasation. Interleukin-1 beta (IL-1β) is involved in the process of human embryo implantation and placenta development. Here, we used an in vitro model to investigate whether sLeX and LeY are playing a role in the embryo implantation process mediated by IL-1β. Our results are showing that the expression of cell surface sLeX was enhanced in endometrial RL95-2 cells after exposure to IL-1β. RT-qPCR detection indicated that the transcript level of glycosyltransferase gene fucosyltransferase 3 (FUT3) was significantly elevated and that of FUT4/7 and ST3 beta-galactoside alpha-2,3-sialyltransferase 3/4 (ST3GAL3/4) were decreased by treatment with IL-1β. Modulatory role of glycosyltransferase FUT3 on sLeX biosynthesis was determined by FUT3 siRNA transfection in RL95-2 cells. Results showed that the expression level of sLeX was suppressed, but no change was observed in regard to LeY. Moreover, IL-1β promoted the HTR-8/SVneo trophoblast spheroids attachment to the RL95-2 endometrial monolayer, which was partially blocked by anti-sLeX antibody and FUT3 knockdown. Gene expression analysis of the RNA-seq transcriptome data from human secretory endometrium demonstrated a significantly higher level of FUT3 in the mid-secretory phase compared to the early secretory phase, which was correlated with the expression of IL1B. In summary, the inflammatory microenvironment at the fetomaternal interface can regulate the glycosylation pattern of endometrial cells at the time of implantation. SLeX can be significantly induced by IL-1β via increasing FUT3 expression, which facilitates the trophoblast adhesion during embryo implantation.