scholarly journals Insulin exposed endometrial epithelial cells cultured in a microfluidic device alters transcripts involved in translation that may contribute to reduced implantation capacity of the endometrium.

2021 ◽  
Author(s):  
Soo Young Baik ◽  
Haidee Tinning ◽  
Dapeng Wang ◽  
Niamh Forde

Obesity is a rapidly growing public health issue among women of reproductive age. It is also associated with decreased reproductive function including implantation failure. Implantation failure can result from a myriad of factors including impaired gametes and endometrial dysfunction. The mechanisms of how obesity-related hyperinsulinaemia disrupts endometrial function and implantation are poorly understood. Our study aims to investigate potential mechanisms by which insulin alters endometrial transcript expression, which may affect endometrial receptivity. Ishikawa cells mimicking human endometrial epithelium were seeded into a microfluidics organ-on-chip device to produce an in vitro endometrium. Syringe pump was attached to the microfluidics device to deliver three varying treatments into Ishikawa cells: 1) media control 2) vehicle control (PBS acidified to pH3 with acetic acid) 3) Insulin (2mg/mL) at a constant flow rate of 1uL/min for 24 hours to mimic secretion in vivo. Three biological replicates were obtained. Insulin-induced transcriptomic response of the in vitro endometrium was quantified via RNA sequencing, and subsequently analysed using DAVID and Webgestalt to identify Gene Ontology (GO) terms and signalling pathways. A Total of 29 transcripts showed differential expression levels across two comparison groups (control v vehicle control; vehicle control v insulin). There were nine transcripts significantly differentially expressed in vehicle control v insulin group (p<0.05). Functional annotation analysis of transcripts altered by insulin (n=9) identified three significantly enriched GO terms: SRP-dependent cotranslational protein targeting to membrane, poly(A) binding, and RNA binding (p<0.05). Over-representation analysis found three significantly enriched signalling pathways relating to insulin-induced transcriptomic response: protein export, glutathione metabolism, and ribosome pathways (p<0.05). Insulin-induced dysregulation of biological functions and pathways highlight potential mechanisms by which high insulin concentrations within maternal circulation may perturb endometrial receptivity.

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Pingping Xue ◽  
Wenbo Zhou ◽  
Wenqiang Fan ◽  
Jianya Jiang ◽  
Chengcai Kong ◽  
...  

Abstract Background Recurrent implantation failure (RIF) is a major limitation of assisted reproductive technology, which is associated with impaired endometrial receptivity. Although N6-methyladenosine (m6A) has been demonstrated to be involved in various biological processes, its potential role in the endometrium of women with RIF has been poorly studied. Methods Global m6A levels and major m6A methyltransferases/demethylases mRNA levels in mid-secretory endometrium from normal and RIF women were examined by colorimetric m6A quantification strategy and quantitative real-time PCR, respectively. The effects of METTL3-mediated m6A modification on embryo attachment were evaluated by an vitro model of a confluent monolayer of Ishikawa cells co-cultured with BeWo spheroids, and the expression levels of homeo box A10 (HOXA10, a well-characterized marker of endometrial receptivity) and its downstream targets were evaluated by quantitative real-time PCR and Western blotting in METTL3-overexpressing Ishikawa cells. The molecular mechanism for METTL3 regulating HOXA10 expression was determined by methylated RNA immunoprecipitation assay and transcription inhibition assay. Results Global m6A methylation and METTL3 expression were significantly increased in the endometrial tissues from women with RIF compared with the controls. Overexpression of METTL3 in Ishikawa cells significantly decreased the ration of BeWo spheroid attachment, and inhibited HOXA10 expression with downstream decreased β3-integrin and increased empty spiracles homeobox 2 expression. METTL3 catalyzed the m6A methylation of HOXA10 mRNA and contributed to its decay with shortened half-life. Enforced expression of HOXA10 in Ishikawa cells effectively rescued the impairment of METTL3 on the embryo attachment in vitro. Conclusion Increased METTL3-mediated m6A modification represents an adverse impact on embryo implantation by inhibiting HOXA10 expression, contributing to the pathogenesis of RIF.


2021 ◽  
Author(s):  
Mi Han ◽  
Yi Cao ◽  
Wenjie Zhou ◽  
Mingjuan Zhou ◽  
Xiaowei Zhou ◽  
...  

Abstract Impaired endometrial receptivity is the main cause of recurrent implantation failure (RIF), however, its underlying mechanism is unclear. In this study, we found that HMGB1 expression was significantly decreased in the implantation phase endometrium in the control group (patients with tubal infertility who successfully achieved conception after the first embryo transfer) (P = 0.006). However, the expression levels of HMGB1 mRNA and protein were significantly upregulated during the implantation phase in endometrial tissues obtained from patients with RIF compared to those in the control group (P = 0.001), consistent with the results of genome-wide expression profiling. Moreover, in vitro assays showed that increased expression of HMGB1 in human endometrial epithelial cells cause marked deficiency in supporting blastocysts and human embryonic JAR cell adhesion, mimicking the process of embryo adhesion. However, overexpression of HMGB1 had no effect on cell proliferation and in-vitro decidualization in a human endometrial stromal cell line (T-HESCs) and in primary human endometrial stromal cells (HESCs). These findings indicate that increased HMGB1 levels suppressed the adhesion capability of epithelial cells, contributing to impaired endometrial receptivity in patients with recurrent implantation failure. This characteristic can be used as a target for detecting and treating recurrent implantation failure in clinical practice.


2021 ◽  
Vol 27 (4) ◽  
Author(s):  
Alexander M Kotlyar ◽  
Ramanaiah Mamillapalli ◽  
Valerie A Flores ◽  
Hugh S Taylor

Abstract Endometriosis is a widespread gynecologic condition affecting up to 15% of women of reproductive age. The Janus kinase/signal transducer and activator of transcription (JAK/STAT3) pathway is upregulated in endometriosis and is a therapeutic target. Here we sought to determine the effect of Tofacitinib, a JAK inhibitor in widespread clinical use, on JAK/STAT signaling in endometriosis and lesion growth. Endometriosis was surgically induced in C57BL/6 mice using homologous uterine horn transplantation. Lesions were allowed to form over 4 weeks followed by Tofacitinib (10 mg/kg) or vehicle administered by oral gavage over 4 weeks. Tofacitinib treatment in vivo led to endometriosis lesion regression and reduced adhesion burden compared to vehicle treatment. In vitro studies on Ishikawa cells showed that Tofacitinib reduced hypoxia-inducible factor 1α and vascular endothelial growth factor mRNA levels at 12 and 24 h. Western blot analysis showed that Tofacitinib effectively reduced STAT3 phosphorylation in Ishikawa cells and human primary stromal and epithelial cells from eutopic endometrium of patients with and without endometriosis. This study suggests that the inhibition of JAK/STAT signaling using Tofacitinib may be a viable method for the treatment of endometriosis.


Reproduction ◽  
2020 ◽  
Vol 159 (6) ◽  
pp. 733-743 ◽  
Author(s):  
Qian Chen ◽  
Yong Fan ◽  
Xiaowei Zhou ◽  
Zheng Yan ◽  
Yanping Kuang ◽  
...  

Some studies have demonstrated that the implantation rate of fresh transfer cycles is lower in the gonadotropin-releasing hormone antagonist (GnRH-ant) protocol than in the GnRH agonist (GnRH-a) protocol during in vitro fertilization (IVF). This effect may be related to endometrial receptivity. However, the mechanisms are unclear. Here, endometrial tissues obtained from the mid-secretory phase of patients treated with GnRH-a or GnRH-ant protocols and from patients on their natural cycle were assessed. Endometrial expression of B-type creatine kinase (CKB), which plays important roles in the implantation phase, was significantly reduced in the GnRH-ant group. At the same time, expression of the endometrial receptivity marker HOXA10 was considerably reduced in the GnRH-ant group. GnRH-ant exposure in endometrial epithelial cells (EECs) in vitro decreased CKB expression and ATP generation and blocked polymerization of actin. Furthermore, in vitro GnRH-ant-exposed Ishikawa cells showed enhanced F-actin depolymerization, and these effects were rescued by CKB overexpression. Similar effects were observed after CKB knockdown, and these effects were rescued by CKB overexpression. Moreover, cell migration was decreased in CKB-knockdown Ishikawa cells compared with that in control cells, and this effect was also rescued by CKB overexpression. Overall, these findings showed that GnRH-ant affected CKB expression in EECs, resulting in cytoskeletal damage and migration failure. These results provide insight into the roles and molecular mechanisms of GnRH-ant treatment in the endometrium.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Dan Zhang ◽  
Mi Han ◽  
Mingjuan Zhou ◽  
Mengyu Liu ◽  
Yan Li ◽  
...  

Abstract Background The gonadotropin-releasing hormone (GnRH) antagonist protocol for in vitro fertilization (IVF) often leads to lower pregnancy rates compared to the GnRH agonist protocol. Decreased endometrial receptivity is one reason for the lower success rate, but the mechanisms underlying this phenomenon remain poorly understood. The S100 calcium protein P (S100P) is a biomarker for endometrial receptivity. Both GnRH antagonist and S100P are involved in mediating cell apoptosis. However, the involvement of S100P in reduced endometrial receptivity during the GnRH antagonist protocol remains unclear. Methods Endometrial tissue was collected at the time of implantation window from patients undergoing the GnRH agonist (GnRH-a) or GnRH antagonist (GnRH-ant) protocols, as well as from patients on their natural cycles. Endometrial cell apoptosis and expression levels of S100P, HOXA10, Bax, and Bcl-2 were assessed. Ishikawa cells were cultured to evaluate the effects that GnRH antagonist exposure or S100P up- or down- regulation had on apoptosis. Results Endometrial tissue from patients in the GnRH-ant group showed elevated apoptosis and decreased expression of the anti-apoptotic marker Bcl-2. In addition, endometrial expression of S100P was significantly reduced in the GnRH-ant group, and expression of HOXA10 was lower. Immunofluorescence colocalization analysis revealed that S100P was mainly distributed in the epithelium. In vitro experiments showed that knockdown of S100P in Ishikawa cells induced apoptosis, decreased expression of Bcl-2, while overexpression of S100P caused the opposite effects and decreased expression of Bax. Furthermore, endometrial epithelial cells exposed to GnRH antagonist expressed lower levels of S100P and Bcl-2, increased expression of Bax, and had higher rates of apoptosis. The increased apoptosis induced by GnRH antagonist treatment could be rescued by overexpression of S100P. Conclusions We found that GnRH antagonist treatment induced endometrial epithelial cell apoptosis by down-regulating S100P, which was detrimental to endometrial receptivity. These results further define a mechanistic role for S100P in contributing to endometrial apoptosis during GnRH antagonist treatment, and suggest that S100P is a potential clinical target to improve the success of IVF using the GnRH antagonist protocol.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
T T T N Nguyen ◽  
Y S S Kwok ◽  
S Russell ◽  
C Librach

Abstract Study question Could non-autologous platelet lysate (PL) increase attachment of HTR–8 spheroids in vitro to primary endometrial epithelial cells (EECs) from patients with recurrent implantation failure (RIF)? Summary answer Increased quantity of HTR–8 spheroids attached to primary EECs, isolated from patients with RIF, suggests in vitro treatment with non-autologous PL could improve endometrial receptivity. What is known already Inadequate endometrial receptivity and thickness are major causes for RIF. Recent studies suggest that platelet-rich plasma (PRP) may improve pregnancy outcomes for RIF and/or thin endometrium (TE) patients. Our previous results show that a commercially sourced and non-autologous human PRP/PL (HPL) promotes EC proliferation in vitro, suggesting that HPL may help to standardize future clinical treatments. In addition to EC proliferation, HPL treatment may improve embryo attachment to primary EECs isolated from patients with a history of RIF. In vitro attachment assays with trophoblast spheroids (embryo model) could help elucidate the effect of HPL on endometrial receptivity in RIF patients. Study design, size, duration Endometrial tissue was collected from nine RIF patients at the CReATe Fertility Centre, Toronto, Canada (Veritas REB#16580): five with (RIF+TE) and four without a TE (RIF only). Primary EECs were enzymatically isolated and treated with serum-free culture media (SFM) or 1% HPL in SFM for 48 hours before performing the attachment assay. Trophoblast cells (HTR–8/SVneo) were grown in suspension on a rocker to form 70–100 uM spheroids over 24 hours before use in the assay. Participants/materials, setting, methods Spheroids were fluorescently labelled with calcein-AM for 30 minutes and size-selected to capture spheroids similar in size to a human blastocyst. Spheroids were seeded on top of EEC monolayers and calcein fluorescence was immediately measured by a spectrophotometer. Following the 1-hour incubation, unattached spheroids were aspirated, and fluorescence was measured again. Spheroids were also individually quantified by fluorescent microscopy and ImageJ™ software. The percentage of spheroid attachment was calculated for calcein fluorescence and ImageJ™ quantification. Main results and the role of chance The HTR–8/SVneo cell line, derived from human first-trimester extravillous trophoblast cells (EVT), has been shown to be a suitable cell line to assess adhesion and invasion in vitro. Trophoblast spheroids generated from this cell line visually resembled a blastocyst and maintained expression of the EVT and implantation biomarkers: GATA3, ITGA5, and LIF. Primary EECs, treated for 48 hours with SFM supplemented with 1% commercially sourced and non-autologous HPL, overall exhibited increased attachment to HTR–8 spheroids. The percentage of spheroid attachment, as measured by fluorescence alone, significantly increase from 47.98% to 64.27% (P &lt; 0.01) of seeded spheroids in RIF+TE EEC cultures, and from 48.12% to 85.77% (P &lt; 0.001) of seeded spheroids in RIF only EEC cultures. Quantification by fluorescent microscopy and ImageJ™ software for individual calcein-stained spheroids, revealed a significant increase in spheroid attachment, from 57.52% to 86.5% (P &lt; 0.01) in RIF+TE EEC cultures, and from 42.58% to 68.90% (P &lt; 0.01) in RIF only EEC cultures. Limitations, reasons for caution Although there was a positive correlation between calcein fluorescence and spheroid quantity, quantification by fluorescence alone may be unreliable due to the variable numbers of cells in each spheroid. Our data suggest a more precise increase in attachment is detected when quantified by fluorescent microscopy and ImageJ™ software. Wider implications of the findings: We report a method for functional assessment of endometrial receptivity in vitro. HPL appears to promote implantation in RIF patients in a model of embryo attachment. We predict that the observed increase in attachment is due to increased endometrial receptivity gene expression, which will be our next investigative avenue. Trial registration number N/A


2020 ◽  
Author(s):  
Songhee Jeon ◽  
Quan Feng Liu ◽  
Hua Cai ◽  
Ha Jin Jeong ◽  
Su-Hyun Kim ◽  
...  

Abstract Background: BaelanChagsangBang (BCB), a herbal formulation consisting of eleven herbs, may be prescribed as a reproductive functional supplement to improve ovulation and implantation during the treatment of infertility and recurrent abortion in Korean Medicine. This study aimed to investigate the effects and action mechanisms of water-extracted BCB on endometrial receptivity and blastocyst implantation under normal conditions and in a mifepristone (RU486)-induced implantation failure murine model.Methods: In vitro, the antioxidant potentials of BCB were evaluated using DPPH and superoxide anion radical scavenging assays and a DCFH-DA assay, and the cytotoxic and cytoprotective effects of BCB were confirmed using an MTT assay. In vivo, C57BL/6 female mice (n = 6 per group) orally received BCB (300 mg/kg/day), a dose similar to that used clinically, from 7 days before pregnancy until the end of the experiment. On day 4 of pregnancy, RU486 (4 mg/kg) was injected subcutaneously to induce implantation failure. The effect of BCB on embryo implantation was evaluated by implantation rate analysis, histological examination, and western blotting of uterus tissues.Results: BCB water extract showed strong anti-oxidative and cytoprotective effects in vitro. In vivo administration of BCB water extract increased the number of newborn pups in BCB-treated mice versus sham-treated mice under normal conditions and improved the number of implantation sites in pregnant mice despite RU486 injection. BCB increased the protein levels of cyclooxygenase-2 and inducible nitric oxide synthase through IκB activation. Moreover, the expression levels of matrix metalloproteinases (MMPs) at uterus implantation sites were up-regulated in the BCB-treated group as compared with those in the RU486-treated group. Conclusion: These results show BCB improved embryo implantation through IκB activation in our mouse model and suggest that BCB has therapeutic potential in the context of poor endometrial receptivity.


2021 ◽  
Vol 22 (18) ◽  
pp. 10082
Author(s):  
Aleksandra E. Mrozikiewicz ◽  
Marcin Ożarowski ◽  
Piotr Jędrzejczak

Currently, infertility affects 8–12% of reproductive age couples worldwide, a problem that also affects women suffering from recurrent implantation failure (RIF). RIF is a complex condition resulting from many physiological and molecular mechanisms involving dynamic endometrium–blastocyst interaction. The most important are the endometrial receptivity process, decidualization, trophoblast invasion, and blastocyst nesting. Although the exact multifactorial pathogenesis of RIF remains unclear, many studies have suggested the association between hormone level imbalance, disturbances of angiogenic and immunomodulatory factors, certain genetic polymorphisms, and occurrence of RIF. These studies were performed in quite small groups. Additionally, the results are inconsistent between ethnicities. The present review briefly summarizes the importance of factors involved in RIF development that could also serve as diagnostic determinants. Moreover, our review could constitute part of a new platform for discovery of novel diagnostic and therapeutic solutions for RIF.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yuhao Zhao ◽  
Dongmei He ◽  
Hong Zeng ◽  
Jiefeng Luo ◽  
Shuang Yang ◽  
...  

Abstract Background Poor endometrial receptivity is a major factor that leads to recurrent implantation failure. However, the traditional method cannot accurately evaluate endometrial receptivity. Various studies have indicated that microRNAs (miRNAs) are involved in multiple processes of embryo implantation, but the role of miRNAs in endometrial receptivity in patients with recurrent implantation failure (RIF) remains elusive. In the present study, we investigated the presence of pinopodes and the roles of miR-30d-5p, suppressor of cytokine signalling 1 (SOCS1) and the leukaemia inhibitory factor (LIF) pathway in women with a history of RIF during the implantation window. Methods Endometrial tissue samples were collected between January 2018 to June 2019 from two groups of women who underwent in vitro fertilisation and embryo transfer (IVF-ET) or frozen ET. The RIF group included 20 women who underwent ≥ 3 ETs, including a total of ≥ 4 good-quality embryos, without pregnancy, whereas the control group included 10 women who had given birth at least once in the past year. An endometrial biopsy was performed during the implantation window (LH + 7). The development of pinopodes in the endometrial biopsy samples from all groups was evaluated using scanning electron microscopy (SEM). Quantitative reverse transcription-polymerase chain reaction and western blotting were used to investigate the expression levels of miR-30d-5p, SOCS1, and the LIF pathway. Results The presence of developed pinopodes decreased in patients with RIF on LH + 7. The expression level of miR-30d-5p decreased in the endometria during the implantation window of patients with RIF, whereas the mRNA and protein levels of SOCS1 were significantly higher in the RIF group than in the control group. Furthermore, a negative correlation was observed between the expression of miR-30d-5p and SOCS1 (r2 = 0.8362). In addition, a significant decrease in LIF and p-STAT3 expression was observed during the implantation window in patients with RIF. Conclusions MiR-30d-5p and SOCS1 may be potential biomarkers for endometrial receptivity. Changes in pinopode development and abnormal expression of miR-30d-5p, SOCS1 and LIF pathway in the endometrium could be the reasons for implantation failure.


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