Late Proliferative Phase Research Articles

Varied cellular abnormalities in thin vs. normal endometrium in recurrent implantation failure by single-cell transcriptomics

BackgroundReduced endometrium thickness and receptivity are two important reasons for recurrent implantation failure (RIF). In order to elucidate differences between these two types of endometrial defects in terms of molecular signatures, cellular interactions, and structural changes, we systematically investigated the single-cell transcriptomic atlas across three distinct groups: RIF patients with thin endometrium (≤ 6 mm, TE-RIF), RIF patients with normal endometrium thickness (≥ 8 mm, NE-RIF), and fertile individuals (Control).MethodsThe late proliferative and mid-secretory phases of the endometrium were collected from three individuals in the TE-RIF group, two in the NE-RIF group, and three in the control group. The study employed a combination of advanced techniques. Single-cell RNA sequencing (scRNA-seq) was utilized to capture comprehensive transcriptomic profiles at the single-cell level, providing insights into gene expression patterns within specific cell types. Scanning and transmission electron microscopy were employed to visualize ultrastructural details of the endometrial tissue, while hematoxylin and eosin staining facilitated the examination of tissue morphology and cellular composition. Immunohistochemistry techniques were also applied to detect and localize specific protein markers relevant to endometrial receptivity and function.ResultsThrough comparative analysis of differentially expressed genes among these groups and KEGG pathway analysis, the TE-RIF group exhibited notable dysregulations in the TNF and MAPK signaling pathways, which are pivotal in stromal cell growth and endometrial receptivity. Conversely, in the NE-RIF group, disturbances in energy metabolism emerged as a primary contributor to reduced endometrial receptivity. Additionally, using CellPhoneDB for intercellular communication analysis revealed aberrant interactions between epithelial and stromal cells, impacting endometrial receptivity specifically in the TE-RIF group.ConclusionOverall, our findings provide valuable insights into the heterogeneous molecular pathways and cellular interactions associated with RIF in different endometrial conditions. These insights may pave the way for targeted therapeutic interventions aimed at improving endometrial receptivity and enhancing reproductive outcomes in patients undergoing ART. Further research is warranted to validate these findings and translate them into clinical applications for personalized fertility treatments.Trial registrationNot applicable.

Endometrial Proliferative Phase-Centered View of Transcriptome Dynamics across the Menstrual Cycle.

The endometrium, the inner mucosal lining of the uterus, undergoes complex molecular and cellular changes across the menstrual cycle in preparation for embryo implantation. Transcriptome-wide analyses have mainly been utilized to study endometrial receptivity, the prerequisite for successful implantation, with most studies, so far, comparing the endometrial transcriptomes between (i) secretory and proliferative endometrium or (ii) mid-secretory and early secretory endometrium. In the current study, we provide a complete transcriptome description of the endometrium across the entire menstrual cycle and, for the first time, comprehensively characterize the proliferative phase of the endometrium. Our temporal transcriptome analysis includes five time points including the mid-proliferative, late proliferative (peri-ovulatory phase), early secretory, mid-secretory, and late secretory phases. Thus, we unveil exhaustively the transitions between the consecutive proliferative and secretory phases, highlighting their unique gene expression profiles and possible distinct biological functions. The transcriptome analysis reveals many differentially expressed genes (DEGs) across the menstrual cycle, most of which are phase-specific. As an example of coordinated gene activity, the expression profile of histone-encoding genes within the HIST cluster on chromosome 6 shows an increase in cluster activity during the late proliferative and a decline during the mid-secretory phase. Moreover, numerous DEGs are shared among all phases. In conclusion, in the current study, we delineate the endometrial proliferative phase-centered view of transcriptome dynamics across the menstrual cycle. Our data analysis highlights significant transcriptomic and functional changes occurring during the late proliferative phase-an essential transition point from the proliferative phase to the secretory phase. Future studies should explore how the biology of the late proliferative phase endometrium impacts the achievement of mid-secretory endometrial receptivity or contributes to molecular aberrations leading to embryo implantation failure.

Relationship Between Menstrual Cycle and Suicide Based on Histo-Pathological Study of Cadaver Uterus in a Tertiary Care Center, South India

Suicide is a global health concern. The risk of suicide is more in females compared to males. Reproductive health related factors are the major reason for this increasing risk. The aim of the study is to find out the relationship between menstruation and suicide and to find out if there is any relationship exists between any of the other phases of menstrual cycle and suicidal behaviour. Hospital based cross sectional study was conducted in the Department of Forensic Medicine, Government Medical College, Thrissur which is a tertiary care centre . The study was done for a period of one year, from August 2015 to July 2016. The final sample size attained i.e the uterus specimens of reproductive age group during the study period is 100. Thus 50 were taken as cases and the other 50 who died of any other cause other than suicide were taken as control. Majority of the study participants belongs to 20 years of age group among cases. Most of our study participants were married in our study, majority of the study participants were above poverty line, no specific history of motivation towards suicide was found in majority of the study participants followed by psychiatric problems and family problems. Hanging was the most common method used for suicide. Among the cases majority of the study participants were in the late proliferative phase. In our study majority of the study participants committed suicide in the early proliferative phase.

Evaluation of endometrial receptivity in women with unexplained infertility by shear wave elastography

ObjectivesThe endometrium of most unexplained infertility (UI) patients has been altered histologically. Shear wave elastography (SWE) is utilized to assess the signature of living tissue. This study aimed to explore the value of SWE in evaluating endometrial receptivity (ER) in UI patients.MethodsIn total, 59 UI patients (UI group) and 52 normal control women (NC group) who received fertility consultation in our hospital were included between January 2022 and June 2023. We divided them into the late-proliferative phase of UI group (LPUI; n = 59), mid-secretory phase of UI group (MPUI; n = 41), late-proliferative phase of NC group (LPNC; n = 52), and mid-secretory phase of NC group (MPNC; n = 45). Transvaginal ultrasonography and SWE were performed during the LP and MP. Endometrial thickness (EMT), uterine artery pulsatility index (UA-PI), endometrial mean elasticity (E-mean), and mean shear wave velocities (SWV-mean) were measured.ResultsThere were significant differences in E-mean, SWV-mean, EMT, and UA-PI between the UI group and the NC group during both the LP and MP (p MPNC vs MPUI < 0.05, p LPNC vs LPUI < 0.05). E-mean and SWV-mean decreased with increasing EMT but increased with increasing UA-PI (p < 0.05). The most effective parameter for evaluating ER in UI patients is the E-mean (AUC = 0.89).ConclusionsUI patients exhibited thinner endometrium, increased endometrial stiffness, and poor endometrial blood perfusion. E-mean was the most effective parameter to evaluate ER in UI patients. The study preliminarily proved that SWE is a promising non-invasive tool for evaluating the condition of endometrium.Critical relevance statementThis study aimed to explore the significance of endometrial elasticity measured by SWE in evaluating patients with UI. The findings revealed a correlation between EMT, UA-PI, and E-mean. Endometrial elasticity can serve as an effective indicator for predicting ER.Key points1. To explore the significance of endometrial elasticity in assessing patients with UI.2. The endometrium of UI patient exhibited thinness, stiffness, and poor blood perfusion.3. Endometrial elasticity serves as a valuable indicator for evaluating endometrial receptivity.Graphical

Monitoring Contractility of Junctional Zone Endometrium across Menstrual Cycle Using the ElectroUteroGraph (EUG): A Clinical Evaluation

(1) Background: Abnormal uterine contractility for nonpregnant women has been associated with gynecological pathologies and infertility. The objective of this study was to evaluate the ability of a novel monitoring technique to assess the contractility of the nongravid uterus using a simple, standardized, direct, in vivo methodology during the different phases of the menstrual cycle. (2) Methods: Twenty-six healthy women of reproductive age (28–48 years) were recruited. An ElectroUteroGraph (EUG) was used to measure the electrical activity from the contractility of the junctional zone endometrium (JZE) across the menstrual cycle. Derived recordings were separated into the early proliferative (EP) (n = 10), late proliferative (LP) (n = 31), early luteal (EL) (n = 27), and late luteal (LL) (n = 12) phases of the menstrual cycle. EUG recordings were performed by inserting a flexible electrode array into the endometrial cavity. (3) Results: Waveforms that were measured from the electrode closer to the fundus (1 cm distance) were processed. The Root-Mean-Square (RMS) Voltage Amplitude (VJZE-RMS) (in μV) and the Mean Frequency (fJZE-mean) (in cycles/min) of the JZE’s electrical activity, as direct indicators of the intensity and frequency changes in the JZE’s contractions, were extracted from the recorded waveforms. There was a trend in the median values of the VJZE-RMS decreasing from the EP to the LP phase (247–158 μV). During the EL phase, an upward trend was observed (158–374 μV, p &lt; 0.05), reaching its highest value during the LL phase (374–477 μV, p &lt; 0.05) when compared to the LP phase. The fJZE-mean showed the opposite trend, increasing from 2.5 cycles/min during the EP phase to 2.96 cycles/min during the LP phase. During the EL phase, a downward trend was observed (2.96–2.37 cycles/min), continuing to fall to 1.33 cycles/min, in the LL phase, with p &lt; 0.05 when compared to the previous three phases. (4) Conclusions: The novel in vivo monitoring technique has shown clinically, for the first time, significant electrical activity differences in the different sub-phases of the menstrual cycle, recorded in a safe and painless way.

Expression of HOXA10 and HOXA11 in the endometrium of infertile patients with chronic endometritis.

The study aimed to evaluate the impact of CE on the expression of HOXA10 and HOXA11 during the late proliferative phase in the endometrium of infertile women. A prospective, translational cohort study was conducted in partnership with the Hospital Universitário Antônio Pedro in Niterói and the Clínica Ginendo in Rio de Janeiro after approval by the Ethics Committee. The patients were selected to participate in the study after showing an indication for hysteroscopy. All participants were divided into three groups: infertile women with endometritis (n=10), infertile women without endometritis (n=17) and fertile women without endometritis (n=10). At hysteroscopy, two endometrial samples were obtaneid, with one sent for histopathological examination per the gynecologist's request and the other used for immunohistochemistry procedures to evaluate the expression of CD138, HOXA10 and HOXA11. CD138 was used to confirm the diagnosis of CE. The analysis of HOXA10 and HOXA11 was performed using the HScoring method for immunohistochemistry with polyclonal antibodies. Women with and without endometritis had lower HOXA10 and HOXA11 expression values than women in the control group (fertile women without endometritis). The expression of HOXA10 and HOXA11 during the proliferative phase is not significantly different between infertile women with endometritis and infertile women without endometritis. Translational studies with a larger number of patients should be performed.

Особенности изменения гидродинамического сопротивления в сосудах микроциркуляторного русла легких при COVID-19 по результатам морфометрического исследования

Introduction. The nature of damage to the body in COVID-19 is of major interest; however, the cardiac mechanisms of death have not been fully studied. The causes of deaths from CVDs require a search for heart failure mechanisms, one of which is an increased burden on the right ventricle due to changes in the affected pulmonary blood vessels. The aim was to assess changes in hydrodynamic resistance in the pulmonary microvasculature in accordance with the variant of the prevailing pathological process in them and the COVID-19 phase. Materials and methods. We performed clinical and morphological analyses of 20 lethal cases with the primary diagnosis of coronavirus infection caused by SARS-CoV-2. We used morphometry to measure the internal diameter of arterioles and venules, the specific capillary area (SCA), and the total radius of the capillary bed. The vascular radius formed the basis for calculating the hydrodynamic resistance in the sections of the microvasculature of the pulmonary circulation. Results. The exudation phase is accompanied by an increased lumen of arterioles and venules against the background of a decreased specific density of the capillary bed. In the early proliferation phase, the capillary bed reduces significantly, and dilatation is replaced by spastic manifestations in arterioles and, to a lesser extent, in venules. The late proliferative phase has similar reduction levels in the total capillary radius and the degree of vasoconstriction of arterioles especially in the zone of increased airiness and grown connective tissue. Conclusion. The reduced capillary bed is of primary importance in increasing the calculated hydrodynamic resistance in the lung tissue during COVID-19. The growth in the average calculated hydrodynamic resistance in the lung tissue occurs to a greater extent during the proliferative phases (early and late) of COVID-19 infection. Keywords: COVID-19, SARS-CoV-2, lungs, vessels

Delta and kappa opioid receptors in human endometrium during the menstrual cycle: Expression and localization

ObjectiveEndogenous opioid peptides were reported to be involved in the regulation of reproductive physiology and their precursors and receptors were described in many of the male and female reproductive tissues. Mu opioid receptor (MOR) was described in human endometrial cells and its expression and localization changed during the menstrual cycle. However, there is no data from the distribution of the other opioid receptors: Delta (DOR) and Kappa (KOR). The objective of the present work was to analyze the dynamics of expression and localization of DOR and KOR in human endometrium throughout the menstrual cycle. Study designHuman endometrial samples from different menstrual cycle phases were analyzed by immunohistochemistry. ResultsDOR and KOR were present in all samples analyzed and the protein expression and localization changed throughout the menstrual cycle. Both receptor expression increased during the late proliferative phase and decreased during the late secretory-one, especially in the luminal epithelium. DOR expression was generally higher than KOR expression in all cell compartments. ConclusionsThe presence of DOR and KOR in human endometrium and their dynamic changes during the menstrual cycle join the results previously obtained in MOR suggesting a possible role of opioids in reproduction events related to the human endometrium.

IMPACT OF ESTRADIOL AND ENDOMETRIAL THICKNESS IN FROZEN EMBRYO TRANSFER CYCLES BASED ON PREPARATION PROTOCOL

The value of obtaining late-proliferative phase serum E2 (estradiol) levels in FET (frozen embryo transfer) cycles has been debated. Furthermore, very little data is published regarding the significance of this levels stratified across FET preparation type and if one preparation regimen is clinically superior to another.

Depletion of Scleraxis-lineage cells during tendon healing transiently impairs multi-scale restoration of tendon structure during early healing.

Tendons are composed of a heterogeneous cell environment, with Scleraxis-lineage (ScxLin) cells being the predominant population. Although ScxLin cells are required for maintenance of tendon homeostasis, their functions during tendon healing are unknown. To this end, we first characterized the spatiotemporal dynamics of ScxLin cells during tendon healing, and identified that the overall ScxLin pool continuously expands up to early remodeling healing phase. To better define the function of ScxLin cells during the late proliferative phase of healing, we inducibly depleted ScxLin cells from day 14–18 post-surgery using the Scx-Cre; Rosa-DTR mouse model, with local administration of diphtheria toxin inducing apoptosis of ScxLin cells in the healing tendon. At D28 post-surgery, ScxLin cell depleted tendons (DTRScxLin) had substantial impairments in structure and function, relative to WT, demonstrating the importance of ScxLin cells during tendon healing. Next, bulk RNAseq was utilized to identify the underlying mechanisms that were impaired with depletion and revealed that ScxLin depletion induced molecular and morphological stagnation of the healing process at D28. However, this stagnation was transient, such that by D56 tendon mechanics in DTRScxLin were not significantly different than wildtype repairs. Collectively, these data offer fundamental knowledge on the dynamics and roles of ScxLin cells during tendon healing.

Effects of Menstrual Cycle on Various Morphologies of High-Grade Squamous Intraepithelial Lesions in SurePath™ Liquid-Based Cervical Cytology

Introduction: The morphology of high-grade squamous intraepithelial lesion (HSIL) on Papanicolaou (Pap) smears widely varied, including syncytial aggregates, sheets, and scattered single cells, and no particular cellular pattern is consistently observed. Therefore, this study aimed to determine whether the menstrual cycle affects the cellular pattern of HSILs, an effort to avoid false negatives due to the oversight of scattered small single HSIL cells in the cytological triage of human papillomavirus-positive women. Methods: A total of 147 HSIL samples of liquid-based cytology (LBC) in patients with cervical intraepithelial neoplasia grade 2 or 3 were obtained, and then, the relationship between cellular patterns, such as single-cell-like and syncytial aggregates, and menstrual cycles classified into six phases was analyzed. If a syncytial aggregate was present, the number of cells constituting the aggregate was visually counted under the microscope. Results: HSILs in scattered single cells and small sheets of <6 on LBC samples accounted for 43% (23/54) during the late proliferative phase of the menstrual cycle. A moderately strong statistically significant association was observed between cellular patterns and menstrual cycles (χ² [3] = 9.423, p < 0.05) (Cramer’s V = 0.253). The value of adjusted residuals showed a statistically significant increased proportion of single-cell-like patterns during the late proliferative phase (p < 0.01). Conclusions: The present study demonstrated that HSIL cells in Pap smears in the late proliferation phase have a high frequency of single-cell-like patterns. In human papillomavirus-positive Pap smears with a clean background and predominantly superficial cells, careful microscopic observation by targeting single HSIL cells can potentially reduce false negatives.

Effect of chemotherapy on the uterus of young adult cancer survivors

ObjectiveTo investigate the impact of chemotherapy on the uterus.DesignCross-sectional pilot study.SettingSingle university fertility clinic.Patient(s)Twelve patients with a history of alkylating agent chemotherapy exposure after Hodgkin lymphoma (cancer) vs. 12 normally menstruating women (controls).Intervention(s)The inclusion criteria were age of 18–45 years and consent for endometrial biopsy. The exclusion criteria were the absence of the uterus, completed pelvic radiation, uterine or cervical cancer, and metastatic cancer. Each participant underwent endometrial biopsy and pelvic ultrasound. All study visits were conducted in the late proliferative phase of the menstrual cycle.Main Outcome Measure(s)Uterine volume, blood flow, endometrial thickness, histology, deoxyribonucleic acid methylation pattern, and relative ribonucleic acid (RNA) expression level during the same phase of the menstrual cycle.Result(s)In the study group, visits were conducted at a median of 31.5 (13.5–42.5) months after chemotherapy. The median uterine volume among cancer survivors was 36 (11.3–67) cm3, and that of the general population controls was 39 (13–54) cm3. On histologic examination, there were no cytologic or architectural atypia. The RNA-sequencing analysis revealed poor clustering of both control and treatment samples. However, we identified 3 differentially expressed genes on RNA-sequencing, but there was no concordance found among the differentially expressed genes and deoxyribonucleic acid methylation changes suggesting most likely false-positive results.Conclusion(s)Approximately 2.5 years after chemotherapy, a time at which several survivors of Hodgkin lymphoma may resume family-building, endometrial thickness and endometrial histology were not significantly affected by a history of alkylating agent chemotherapy exposure.

Down-regulation of PBK inhibits proliferation of human endometrial stromal cells in thin endometrium

BackgroundThin endometrium (TE) is a challenging clinical issue in the reproductive medicine characterized by inadequate endometrial thickness, poor response to estrogen and no effective treatments currently. At present, the precise pathogenesis of thin endometria remains to be elucidated. We aimed to explore the related molecular mechanism of TE by comparing the transcriptome profiles of late-proliferative phase endometria between TE and matched controls.MethodsWe performed a bulk RNA-Seq (RNA-sequencing) of endometrial tissues in the late-proliferative phase in 7 TE and 7 matched controls for the first time. Differential gene expression analysis, gene ontology enrichment analysis and protein-protein interactions (PPIs) network analysis were performed. Immunohistochemistry was used for molecular expression and localization in endometria. Human endometrial stromal cells (HESCs) were isolated and cultured for verifying the functions of hub gene.ResultsIntegrative data mining of our RNA-seq data in endometria revealed that most genes related to cell division and cell cycle were significantly inhibited, while inflammation activation, immune response and reactive oxygen species associated genes were upregulated in TE. PBK was identified as a hub of PPIs network, and its expression level was decreased by 2.43-fold in endometria of TE patients, particularly reduced in the stromal cells, which was paralleled by the decreased expression of Ki67. In vitro experiments showed that the depletion of PBK reduced the proliferation of HESCs by 50% and increased the apoptosis of HESCs by 1 time, meanwhile PBK expression was inhibited by oxidative stress (reduced by 76.2%), hypoxia (reduced by 51.9%) and inflammatory factors (reduced by approximately 50%). These results suggested that the insufficient expression of PBK was involved in the poor endometrial thickness in TE.ConclusionsThe endometrial transcriptome in late-proliferative phase showed suppressed cell proliferation in women with thin endometria and decreased expression of PBK in human endometrial stromal cells (HESCs), to which inflammation and reactive oxygen species contributed.

Sonographic Correlation between Endometrial Thickness and Infertility - A systematic review

Background: Infertility is defined as not conceiving after one year of unprotected sex. Apart from age, physical and hormonal misbalance, and lifestyle or environmental factors for infertility; Endometrial thickness has an important role in conception. Females with the 8-12mm endometrial thickness in the late proliferative phase had great chances to get conceive. Aim: To determine the sonographic diagnostic features of the endometriumthickness with Transvaginal high-resolution ultrasound are predictive of infertility. Methods: An electronic database search was performed (Google Scholar, Science Direct, and PubMed) with the data range from 1988 to 2020.All studies, fully-available in English, assessing the endometrial thickness in the gray-scale image on TAS/TVs. Results: Thirty-three articles were found, we evaluated the performance of ultrasound diagnostic techniques, for the measurement of endometrial thickness, our results showed that ultrasound had a high level of diagnostic capability for measuring endometrial thickness. If endometrial thickness is more than 14mm or less than 7mm then chances of pregnancy were zero, so high chances of pregnancy when the endometrial thickness is 8mm to 11mm. Conclusion: We concluded that when the endometrial thickness was increased from 8 mm to 11 mm the chances of pregnancy were maximum, and when the thickness of endometrium was more than 14 mm or, less than 7 mm the pregnancy ratio was almost zero. Transvaginal ultrasound is an excellent imaging modality and its sensitivity is high for the measurement of endometrial thickness Keyword: Transvaginal sonography, endometrial thickness, Infertility

Circulating miRNAs in diabetic retinopathy patients: Prognostic markers or pharmacological targets?

In this study we analyzed the expression of circulating miRNAs, in the serum of diabetic retinopathy (DR) patients. Five miRNAs (hsa-miR-195-5p, hsa-miR-20a-5p, hsa-miR-20b-5p, hsa-miR-27b-3p and hsa-miR-451a) were validated as biomarkers for stratification of DR stages, from the early non-proliferative (NPDR) to the late proliferative (PDR) phase. Furthermore, circulating levels of these miRNAs correlated with retinal hyper-reflective spots (HRS), assessed by optical coherence tomography (OCT). The number of HRS increased with worsening of DR stages. On the contrary, no significant vascular density differences between NPDR and PDR patients were detected by angio-OCT (OCTA). A post-hoc bioinformatics analysis associated these five miRNAs to target genes belonging to the “Tumor Necrosis Factor alfa signaling” pathway, and several molecules were predicted to modify miRNAs expression. In conclusion, correlation between specific circulating miRNAs and intraretinal hyper-reflective spots was demonstrated, confirming that these miRNAs were validated as prognostic biomarkers, and also as potential pharmacological targets, warranting further clinical evaluation to explore novel therapeutics for diabetic retinopathy.

A Novel Molecule in Human Cyclic Endometrium: LncRNA TUNAR Is Involved in Embryo Implantation

Embryo implantation rate remains an inefficient process in in vitro fertilization and embryo transfer (IVF-ET) cycles. The role long non-coding RNA (lncRNA) plays in embryo implantation remains unclear. We aimed to investigate the expression pattern of lncRNA TCL1 upstream neural differentiation-associated RNA (TUNAR) in human cyclic endometrium and clarify the role of TUNAR in the development of endometrial receptivity. Endometrial biopsies were collected at the late proliferative phase, luteinizing hormone (LH) + 2 and LH + 7, from patients with or without recurrent implantation failure (RIF). Real-time RT PCR was performed to detect the level of lncRNAs. After pZW1-snoVector-TUNAR transfection, multiple function of TUNAR in endometrial epithelial cells (EECs) and endometrial stromal cells (ESCs) was investigated. The expression of TUNAR in endometrium was found down-regulated at LH + 7 and up-regulated in RIF patients. In proliferative phase, TUNAR was overwhelmingly more abundant in ESCs and regulated its proliferation. In LH + 7, the difference in the expression of TUNAR between ESCs and EECs was narrowed. Overexpression of TUNAR not only impaired spheroid attachment to EECs, but also inhibited decidualization of ESCs. TUNAR was found expressed in human endometrium for the first time, which might be involved in embryo implantation by modulating the blastocyst attachment to the endometrial epithelium and regulating the proliferation and decidualization of ESCs. Our study helps us to better understand the molecular mechanisms of embryo implantation and may provide a promising biomarker of endometrial receptivity.

The role of unfolded protein response in the pathogenesis of endometriosis: contribution of peritoneal fluid

Research questionEndoplasmic reticulum stress (ERS) is caused by the accumulation of the misfolded or unfolded proteins in the endoplasmic reticulum and induces the unfolded protein response (UPR). Peritoneal fluid is important in the pathogenesis of endometriosis. In this study, the role of UPR associated with ERS in endometriosis, and peritoneal fluid, were investigated. DesignNormal, eutopic and ectopic endometrium tissues were divided into menstrual cycle phases, and endometrial stromal cells (ESC) were treated with 10–20% concentration of control peritoneal fluid and peritoneal fluid obtained from women with endometriosis for 10, 30 and 60 min, and 24 and 48 h. The UPR signalling proteins were analysed immunohistochemically and immunocytochemically. Data were compared statistically. Resultsp-IRE1 was increased in ectopic glandular and stromal cells in the early proliferative phase compared with normal and eutopic endometrium. p-PERK increased in ectopic glandular and stromal cells in the late proliferative phase compared with normal endometrium. ATF6 was increased in ectopic glandular epithelium compared with normal endometrium in the proliferative phases, versus eutopic endometrium in the late secretory phase. p-IRE1 and p-PERK were increased in high concentrations of ESC treated with peritoneal fluid obtained from women with endometriosis for 10, 30 and 60 min compared with controls. In ESC treated with peritoneal fluid from women with endometriosis, p-IRE1 decreased at 24–48 h compared with 30 min. ConclusionsIn endometriosis, UPR pathways are activated as highly dependent on cell type and phase. Also, p-PERK and p-IRE1 increased because of exposure to high-dose peritoneal fluid from women with endometriosis in stromal cells. Our findings provide a basis for further studies searching for a potential biomarker for the diagnosis of endometriosis.

The expression of hepatoma upregulated protein in human endometrium during the menstrual cycle

Aims Human endometrium resists embryo implantation except during the window period. Currently, uterine HURP expression is known to be involved in endometrial stromal proliferation during embryo implantation of mice. Thus, we demonstrated hepatoma up-regulated protein (HURP) expression in the human endometrium during the menstrual cycle, as well as HURP regulation in endometrial stromal cells (ESCs). Materials and methods We collected human endometrial samples from different menstrual cycle phases (early/late proliferative, and early/mid/late secretory), and then analyzed these samples by immunohistochemistry, reverse transcription-polymerase chain reaction, and Western blotting. We also assessed the effects of two sex-steroid hormones, 17β-estradiol (E2) and 4-pregnene-3,20-dione (P4) on the cultured stromal cells. Results HURP protein was localized to the nucleus of the endometrial both epithelial and stromal cells in all stages. Also, HURP mRNA and protein in human endometrial tissue was significantly up-regulated during late-proliferative and secretory phase, compared with early-proliferative phase. In ESCs, HURP expression was regulated by E2, but not P4. Conclusions We indicated that cyclic changes in HURP expression in human normal ESC strongly suggested up-regulation by estrogen. Taken together, since estrogen responses are fundamental in endometrial biology, uterine expression of HURP may be involved in female reproductive function during the menstrual cycle.

Impact of Serum Estradiol Levels Prior to Progesterone Administration in Artificially Prepared Frozen Embryo Transfer Cycles.

Background: The need for endocrine monitoring in artificial cycles for frozen embryo transfer (FET) remains unclear and, more specifically, the value of the late-proliferative phase serum estradiol (E2) levels is with conflicting evidence in current literature.Objective: To investigate whether artificial FET cycles require endocrine monitoring for the serum E2 level prior to initiation of exogenous progesterone administration after an endometrial thickness of 6.5 mm has been reached.Design: One thousand two hundred and twenty-two (n = 1,222) artificial FETs performed in a tertiary center between 2010 and 2015 were subdivided into 3 groups according to the following late-proliferative serum E2 level percentiles: ≤p10 (E2 ≤144 pg/ml; n = 124), p11–p90 (E2 from 145 to 438 pg/ml; n = 977) and >p90 (E2 >439 pg/ml; n = 121).A mixed-effects multilevel multivariable regression analysis was performed to assess the potential effect of the late-proliferative E2 level on the live birth rate (LBR).Results: The level of late-proliferative circulating E2 showed no significant difference in terms of LBR after FET. Specifically, the multivariable regression model demonstrated a LBR of 19.5% for the p11–p90 reference group, compared to 24.4% for the ≤p10 (p = 0.251) and 19.5% for the >p90 group (p = 0.989).Conclusion: In this large retrospective dataset, no association was observed between late-proliferative phase serum E2 levels and LBR following FET in artificially prepared cycles. Although, caution is warranted due to the retrospective nature of the analysis and the potential for unmeasured confounding, we argue that monitoring of the late-proliferative serum E2 levels and using them to guide clinical decision-making (e.g., medication step-up, cycle prolongation or cancelation) may be of questionable value.

Corrigendum. Decreased PECAM1-mediated TGF-β1 expression in the mid-secretory endometrium in women with recurrent implantation failure.

Study question Is recurrent implantation failure (RIF) associated with decreased expression of platelet and endothelial cell adhesion molecule 1 (PECAM1) and transforming growth factor β1 (TGF-β1) in the endometrium during the implantation window? Summary answer The present study demonstrates that the expression of PECAM1 and TGF-β1 is significantly decreased in the mid-secretory endometrium in women with RIF, which may account for embryo implantation failure. What is known already RIF has become a bottleneck issue that hampers the improvement of pregnancy rates in IVF-embryo transfer (IVF-ET). The causes of RIF are complex and may involve the dysregulation of various growth factors, metabolites, and inflammatory cytokines. At present, the precise pathogenesis of RIF has not been elucidated. Study design, size, duration This was a prospective case-control study. Endometrial tissue samples were obtained from January 2014 to December 2016 from two groups of women who had undergone IVF (RIF group, 22 women who underwent ≥3 ETs including a total of ≥4 good-quality embryos without pregnancy, control group, 18 women who conceived in their first treatment cycle). At the same time, samples were obtained from 18 women with infertility secondary to tubal factor in the early proliferative, late proliferative and mid-secretory phases of the menstrual cycle (n = 6 per group). Samples used for isolation of primary human endometrial epithelial cells and stromal cells (HEECs and HESCs) were collected in December 2017 from six women with infertility secondary to tubal factor. Participants/materials, setting, methods We investigated gene expression using integrative whole genome expression microarray analysis, including differentially expressed gene screening, principal component analysis, and functional enrichment analysis. RT-qPCR, western blotting, immunohistochemistry, immunofluorescence co-localization analysis and short hairpin RNA (shRNA) plasmid transfection in Ishikawa cell line, HEECs and HESCs were used to investigate the expression of PECAM1 and TGF-β1. Main results and the role of chance Integrative data mining of whole-genome expression profiles identified cell adhesion as a key regulator in RIF. Database retrieval and literature review screened several novel cell adhesion-related genes that might participate in embryo implantation, which include PECAM1, intercellular adhesion molecule 2 (ICAM2), integrin subunit β2 (ITGB2), selectin P (SELP) and TEK receptor tyrosine kinase (TEK). Among these targets, the mRNA and protein levels of PECAM1 were significantly lower in the RIF group than those in the control group. During the menstrual cycles of women with secondary infertility, the protein expression level of PECAM1 was the lowest in early proliferative phase, slightly increased in late proliferative phase and was the highest in mid-secretory phase. While the expression level of HOXA10, an endometrial receptivity marker, kept at a low level in early proliferative phase and increased in late proliferative phase, then maintained at a high level in the mid-secretory phase. Furthermore, TGF-β1, mediated by PECAM1, was also decreased significantly in the RIF group. Using shRNA-based approach, we demonstrated that the depletion of PECAM1 significantly decreased the expression of TGF-β1 in Ishikawa cells, as well as in primary HEECs and HESCs. These results indicated that PECAM1 and TGF-β1 might play a pivotal role in modulating endometrial receptivity. Limitations reasons for caution Although we have shown that PECAM1 and TGF-β1 were down-regulated in the women with RIF, the molecular mechanism of the effect of the factors on the endometrial receptivity remain unclear. Wider implications of the findings Our findings provide insight into the contribution of PECAM1 and TGF-β1 in regulating implantation, which could be used to develop potential therapeutic methods for RIF. Study funding/competing interest(s) This work was supported by grants from the National Natural Science Foundation of China (Nos. 81771656 and 81370763), Special fund for clinical research of the Chinese Medical Association (No. 16020480664), and the Merck Serono China Research Fund for Fertility Agreement. The authors have no competing interests.