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The human uterus is a complex and dynamic organ whose lining grows, remodels, and regenerates every menstrual cycle or upon tissue damage. Here, we applied single-cell RNA sequencing to profile more the 50,000 uterine cells from both the endometrium and myometrium of five healthy premenopausal individuals, and jointly analyzed the data with a previously published dataset from 15 subjects. The resulting normal uterus cell atlas contains more than 167K cells, representing the lymphatic endothelium, blood endothelium, stromal, ciliated epithelium, unciliated epithelium, and immune cell populations. Focused analyses within each major cell type and comparisons with subtype labels from prior studies allowed us to document supporting evidence, resolve naming conflicts, and propose a consensus annotation system of 39 subtypes. We release their gene expression centroids, differentially expressed genes, and messenger Ribonucleic Acid (mRNA) patterns of literature-based markers as a shared community resource. We identify multiple potential progenitor cells: compartment-wide progenitors for each major cell type and potential cross-lineage multipotent stromal progenitors that may replenish the epithelial, stromal, and endothelial compartments. Furthermore, many cell types and subtypes exhibit shifts in cell number and transcriptomes across different phases of the menstrual cycle. Finally, comparisons between premenopausal, postpartum, and postmenopausal samples revealed substantial alterations in tissue composition, particularly in the proportions of stromal, endothelial, and immune cells. The cell taxonomy and molecular markers we report here are expected to inform studies of both basic biology of uterine function and its disorders., Competing Interests: Competing interests statement:The authors declare no competing interest.

Infertility is an important issue for human reproductive health, with over half of all cases of infertility associated with female factors. Dysfunction of the complex female reproductive system may cause infertility. In clinical practice, female infertility is often treated with oral medications and/or surgical procedures, and ultimately with assisted reproductive technologies. Owing to their excellent biocompatibility, low immunogenicity, and adjustable mechanical properties, hydrogels are emerging as valuable tools in the reconstruction of organ function, supplemented by tissue engineering techniques to increase their structure and functionality. Hydrogel-based female reproductive reconstruction strategies targeting the pathological mechanisms of female infertility may provide alternatives for the treatment of ovarian, endometrium/uterine, and fallopian tube dysfunction. In this review, we provide a general introduction to the basic physiology and pathology of the female reproductive system, the limitations of current infertility treatments, and the lack of translation from animal models to human reproductive physiology. We further provide an overview of the current and future potential applications of hydrogels in the treatment of female reproductive system dysfunction, highlighting the great prospects of hydrogel-based strategies in the field of translational medicine, along with the significant challenges to be overcome.

Patient-derived endometrial biopsies serve as a crucial source for molecular studies, highlighting the necessity for tissue cryopreservation methods that preserve cell viability and tissue morphology with minimal to no impact. The passive slow freezing (PSF) protocol has demonstrated efficacy for cryopreserving endometrial biopsies, allowing for the subsequent isolation of viable epithelial and stromal cells. Vitrification (VT) enables the avoidance of ice crystal formation and could therefore potentially prevent mechanical injury to tissues. In this study, PSF and VT techniques were applied to endometrial biopsies, and the effects of cryopreservation on tissue samples were evaluated using traditional histology. In addition, transmission electron microscopy (TEM), gene expression profiling analyses, the viability of endometrial cells, and the ability to form epithelial organoids were compared between PSF and VT endometrial biopsies in a subset of samples. The histology and TEM studies demonstrated relatively mild cellular and sub-cellular damage in both cryopreservation protocols which did not affect tissue functionality and the formation of the organoids. Additionally, the cryopreservation methodology did not affect the gene expression profile of the 68 endometrial-receptivity associated genes studied. In conclusion, our findings indicate that although current cryopreservation methodologies need further improvements, they still allow us to achieve acceptable cell viability and functionality, showing promising potential for facilitating the utilization of cryopreserved endometrial tissue samples for research purposes., (Copyright © 2024. Published by Elsevier Inc.)

Aim: Endometrial changes in Japanese transgender men (TGM) on testosterone use remain elucidated. This study aims to present TGM with endometrial cancer and insights from a literature review of similar cases. Furthermore, we investigated the correlation between endometrial cancer and severe obesity in TGM who underwent gender-affirming surgery., Methods: Between July 2020 and April 2023, two groups were assessed: 2 TGM with endometrial cancer and 43 TGM without cancer who underwent gender-affirming surgery. A literature review for TGM with endometrial cancer was conducted. Clinical data were retrospectively collected, and histopathological evaluation of female genital organs was performed., Results: Two TGM with endometrial cancer and an additional four similar cases were identified through a literature search. These TGM had severe obesity (body mass index [BMI] ≥30 kg/m 2 ) and long-term testosterone use, indicating a possible link between endometrial cancer and these factors. Subsequently, we investigated the 43 TGM without cancer. We revealed 30% with obesity (BMI ≥25), only three cases of severe obesity (BMI ≥30), and a significant correlation between testosterone use duration and BMI in TGM without cancer. Histological examination revealed focal proliferative endometrium in 51% of cases and polycystic ovarian changes in 77%., Conclusions: Our observations suggest a potential link between severe obesity, prolonged testosterone use, and endometrial cancer in transgender men. Histological changes in the female genital tract highlighted frequent focal proliferative endometrium, even under testosterone therapy. Further research should focus on larger, multi-institutional studies to confirm these findings and establish endometrial cancer screening for Japanese TGM., (© 2024 Japan Society of Obstetrics and Gynecology.)

Study Question: Is topical oestradiol gel effective in promoting endometrial regeneration after a surgical abortion?, Summary Answer: Topical oestradiol gel is effective in promoting endometrial regeneration after a surgical abortion with few side-effects., What Is Known Already: Oestrogen is effective in promoting endometrial regeneration. Transdermal oestrogen has been widely used in clinical practice for endometrial regeneration after induced abortion, but high-level evidence is limited., Study Design, Size, Duration: We conducted a multicentre, superiority, randomized, double-blind, placebo-controlled trial. Between 9 March 2022 and 21 February 2023, 200 women were assigned in a 1:1 ratio to receive either oestradiol gel (treatment) and or oestradiol gel simulant (control) for 28 days. The participants were scheduled to have their endometrial thickness (mm) measured by ultrasonographic scan at 21-23 days post-abortion. The trial was blinded for participants, investigators, medical staff, and statistical analysts until final unblinding., Participants/materials, Setting, Methods: Participants were women undergoing induced abortion within 10 weeks of gestation. A total of 200 participants were enrolled, with 100 in each group. Eighty-eight (88%) in the treatment group and 82 (82%) in the control group completed the study as per the protocol and were included in the per-protocol set (PPS). The intent-to-treat (ITT) analysis included all participants randomized to the study groups and used inverse probability weighting to account for loss to follow-up., Main Results and the Role of Chance: The ITT analysis showed revealed significantly greater endometrial thickness in the treatment group (mean 8.1 ± 2.5 mm) compared to the control group (mean 6.9 ± 2.1 mm) 21-23 days postabortion (mean difference 1.2 mm, 95% CI 0.7 to 1.9; P < 0.001). The median time to menstrual return was shorter in the treatment group (34 days, inter-quartile range [IQR] 30-38) than in the control group (35 days, IQR 32-42), with a difference of -1 day (95% CI -2.3 to -0.9; P = 0.036). No differences were observed in the timing or volume of bleeding in the first post-abortion cycle. The PPS analysis mirrored the ITT findings. Adverse events were minimal (6% versus 8%), and the blood profile, liver, kidney and coagulation test results were comparable between groups (all P > 0.05)., Limitations, Reasons for Caution: Loss to follow-up was 11% in the treatment group and 15% of controls, with no significant difference (P > 0.05). Inconsistencies in the timing of the ultrasonographic scans may have affected the accuracy of endometrial thickness measurements., Wider Implications of the Findings: Our findings suggest that topical oestrogen supplementation immediately after abortion within the first 10 weeks of gestation improves endometrial regeneration and growth, thereby potentially increasing the chances of a successful subsequent pregnancy. Clinical application of these findings may improve endometrial health management practices and provide a perspective on fertility treatment and women's reproductive health., Study Funding/competing Interest(s): This study was supported by a grant (FW-HKKT2021111501900) from Jianmin Pharmaceutical Group Co., Ltd (JMPG), Wuhan, Hubei, China. Both the oestradiol gel and the simulant were provided by JMPG. The funding source had no role in the study. X.Y.L. reports JMPG grant funding paid to their institutions. All other authors declare no competing interests., Trial Registration Number: CHiCTR2100053565., Trial Registration Date: 24 November 2021., Date of First Patient’s Enrolment: 9 March 2022., (© The Author(s) 2024. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

In dairy cows, the processes involved in the resolution of uterine inflammation during the postpartum are closely related to improved fertility during the subsequent lactation period. Little is known, however, about the role and distribution of endometrial immune cell populations during the pre-implantation period. This study was aimed to analyze the endometrial distribution of several mononuclear immune cells (T cells, γδ T cells, B cells and macrophages) in healthy dairy cows during the postpartum, beyond the transition period, looking for its possible association with the parturition-conception interval (PCI) and delayed conception. The quantification of immune cells was evaluated by immunohistochemistry (IHC), and the expression of hormone receptors in immune cells was evaluated by double IHC. Dairy cows were grouped according to their PCI: PCI shorter than or equal to 90 DIM (PCI ≤90 ), PCI between 90 and 120 DIM (PCI 90-120 ), and PCI greater than 150 DIM (PCI ≥150 ). The distribution of endometrial mononuclear immune cells was analyzed by a Generalized Linear Model, and the association of the distribution of mononuclear immune cells with delayed conception was evaluated with a Kaplan-Meier test. The cows from the PCI 90-120 group showed the highest number of endometrial macrophages, and a lower number of B cells than the PCI ≤90 group. Results also showed an association between the lower number of B cells in the endometrium during the pre-implantation period and earlier conception. Also, the present findings indicates that ESR and PR are expressed in the endometrial MØ, T cells, γδ T cells and B cells., Competing Interests: Declaration of Competing Interest I confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome. The manuscript has been read and approved by all authors. There are no other persons who satisfied the criteria for authorship but are not listed. I further confirm that the order of authors listed in the manuscript has been approved by all of them. I am the sole contact for the Editorial process (including Editorial Manager and direct communications with the office) as Corresponding Author. I am responsible for communicating with the other authors about progress, submissions of revisions and final approval of proofs., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Study Question: Can a functional in vitro model, containing the main cellular components of the uterine wall, be generated from cells derived from patient tissues?, Summary Answer: We present a three-dimensional (3D) physiologically relevant, organ-on-a-chip model of the uterine wall containing primary endometrial and myometrial cellular participants, generated from human uterine tissue., What Is Known Already: As a highly dynamic reproductive organ, the human uterus plays fundamental physiological roles in menstruation and childbirth. The endometrial-myometrial junction (EMJ) defines the interface between the inner mucosal layer (endometrium) and outer smooth muscle zone (myometrium) that comprises the uterine wall. The EMJ is implicit in several uterine pathologies of unknown aetiology, including adenomyosis and abnormally invasive placenta; however, despite this, no patient-derived in vitro models of the uterine wall containing all EMJ participants currently exist., Study Design, Size, Duration: We employed microfluidic technology to characterize multiple miniaturized models of the uterine wall. Protocols were tested that included variations in the seeding order of endometrial and myometrial fractions, and the addition of a low viscosity extracellular matrix to influence cell behaviour. Ultimately, functional hormone responses of patient-derived uterine wall models were assessed., Participants/materials, Setting, Methods: Endometrial (n = 9) and myometrial biopsies (n = 4) were enzymatically dissociated to create epithelial, stromal and myometrial cellular fractions. Cell suspensions were seeded into non-adhesive poly(dimethylsiloxane) microfluidic devices containing 5 × 5 microwell arrays. The fate of individual cell types was monitored in real-time using fluorescent tracers, and cell phenotype was characterized by immunocytochemistry. Model functionality was assessed by measuring Ca2+ responses to agonist stimulation, and both insulin-like growth factor binding protein 1 (IGFBP-1) and osteopontin secretion in response to hormone stimulation., Main Results and the Role of Chance: When subjected to microfluidic culture in isolation, endometrial stromal cells and smooth muscle myocytes formed compact spheroids, whilst epithelial cells produced diffuse aggregates. Tri-cultures were established by sequential seeding of individual or combined cell fractions at various ratios. Regardless of the protocol, epithelial cells localized to the outer periphery of tri-culture spheroids, which varied in morphology across the protocols. Incorporation of 5% [v/v] Matrigel® improved the reproducibility of 3D aggregates which exhibited robust self-assembly of a stromal/smooth muscle core encased in epithelium. Exposure of tri-cultures to oestradiol, medroxyprogesterone acetate and cyclic adenosine monophosphate (cAMP) increased secretion of IGFBP-1, which indicates stromal decidualization, and enhanced epithelial cell osteopontin secretion. Stimulation with endothelin-1 induced Ca2+ signalling in myocytes., Limitations, Reasons for Caution: Endometrial and myometrial tissue was collected from relatively few donors. Myometrial tissue was collected from pregnant donors, which may have influenced the myocyte phenotype. Furthermore, endometrial tissue sampling was from women not having a hysterectomy, thus may not include the deeper basalis region, which may limit the physiological mimicry of the final models., Wider Implications of the Findings: Our novel approach to modelling the uterine wall in 3D captures all of the main cell types in a medium-throughput system, enabling the screening of hundreds of cultures in parallel from a single biopsy. This system shows great promise for examining the cellular interplay between physiological cues and EMJ pathologies, such as the impact of uterine peristalsis and cyclical hormones on the pathogenesis of adenomyosis., Study Funding/competing Interest(s): C.B. was supported by an Organ-on-a-Chip Technologies Network Pump Priming Project grant. C.J.H. was supported by a Wellbeing of Women project grant (RG2137), SRI/Bayer and Wellcome Trust IFFS3. D.K.H. was supported by a Wellbeing of Women project grant (RG2137) and MRC clinical research training fellowship (MR/V007238/1). M.Z. is Director and Co-Founder of ScreenIn3D Limited. The other authors declare no conflict of interest., Trial Registration Number: N/A., (© The Author(s) 2024. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology.)

The aims of this study were: To ultrasonographically describe and compare endometrial echogenicity and heterogeneity using digital analysis in normal and bitches suffering from pyometra, cystic endometrial hyperplasia (CEH) and endometritis; and to evaluate the effect of clinical, bacteriological and histopathological uterine parameters on endometrial echogenicity and heterogeneity. Forty-one post pubertal intact bitches were included. According to clinical, ultrasonographic, anatomopathological and histopathological uterine evaluation, the animals were classified as: Pyometra (PYO; n=6); CEH (n=8); Endometritis (END; n=13); Normal group (NG; n=14). Endometrial images were analyzed with ImageJ software to obtain echogenicity and heterogeneity, represented as the mean gray value (MGV) and standard deviation of gray (SDG), respectively. The effect of the group, clinical, bacteriological, ultrasonographic and histological variables on MGV and SDG were analyzed by a generalized linear model. PYO exhibited higher MGV (P<0.01) and SDG (P<0.01) than the other groups. No differences were found among CEH, END and NG for both parameters (P>0.1). Body weight decreased MGV (P<0.01), while increasing degrees of inflammatory reaction (P<0.01), edema (P<0.01), hemorrhages (P<0.01) and vascular congestion (P<0.01) were associated with higher MGV. Inflammatory reaction (P<0.01) and ulceration (P<0.01) increased SDG. Ultrasonographic images evaluated using computer assisted image analysis were useful to differentiate pyometra from other uterine conditions in dogs. However, this technique could not differentiate among CEH, END and NG. Uterine echogenicity and echotexture, which clearly represent the different histopathological patterns, contribute to the diagnosis of the definite diagnosis of some canine uterine diseases., Competing Interests: Declaration of Competing Interest None of the authors have any conflict of interest to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In mammalian species, pregnancy is a complex process that involves the maternal recognition of pregnancy, implantation, decidualization, placentation, and parturition. The innate immune system is composed of cellular components, such as natural killer cells, neutrophils, monocytes, and macrophages, and effector molecules, such as cytokines, interferons, antimicrobial peptides, and complement components. The innate immune system plays a critical role as the first line of defense against infection or inflammation to maintain homeostasis and activate the adaptive immunity. During pregnancy, innate immune cells and effector molecules act on the regulation of innate immunity for host defense and processes such as embryo development, implantation, and placentation at the maternal-conceptus interface. In this review, we describe the components of the innate immune system and their functions at the maternal-conceptus interface to establish and maintain pregnancy in animal species that form hemochorial- or epitheliochorial-type placentas, including humans, rodents, ruminants, and pigs.

We recently demonstrated that conceptus-derived interferon tau (IFNT), responsible for maternal recognition in cattle, acts on the uterus in a dose- and time-dependent manner by upregulating key interferon-stimulated genes (ISGs) in the endometrium. In high producing dairy cows, postpartum uterine infection is a major factor influencing fertility and pregnancy outcome. Lipopolysaccharide (LPS), an endotoxin of Gram-negative bacteria such as Escherichia coli, generates an altered uterine environment by inducing excessive inflammation at the maternal-conceptus interface. Thus, we aimed to investigate whether the endometrial response to IFNT is altered in the presence of LPS. Endometrial explants were isolated from uteri collected at a local abattoir from Holstein Friesian cows (n = 8) during the mid-luteal stage of the estrous cycle, and cultured in RPMI medium for 24 h in 5 % CO 2 in humidified air without (control), or with IFNT (100 ng/mL), a single Day 15 conceptus, LPS (1 μg/mL), both IFNT and LPS, or both a Day 15 conceptus and LPS. Incubation with IFNT and a Day 15 conceptus up-regulated (P < 0.05) well-known classical ISGs (ISG15, OAS1, MX1 and MX2) as well as other candidate ISGs (CMPK2, IFI35, TRIM38 and TNFSF10) and down-regulated expression of IL1B in endometrial explants. Incubation with LPS increased (P < 0.05) abundance of NFKB1 (a key transcription factor involved in inflammatory and immune response), TNFA, IL1B and IL6 (pro-inflammatory cytokines), IL10 (anti-inflammatory cytokine), IL8, CXCL1, CXCL3 and CCL2 (chemokines), and, to a lesser extent, classical ISGs in endometrial explants. However, LPS did not alter endometrial response to IFNT, irrespective of IFNT concentration (1, 10 or 100 ng/mL). Results suggest that the expression of ISGs, up-regulated by conceptus-derived IFNT, is not altered in the endometrium in the presence of LPS; however, the increased expression of inflammation-related genes induced by LPS indicate an altered endometrial immune response that may be associated with compromised pregnancy establishment or pregnancy failure., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Successful embryo implantation relies on synchronized dialog between the embryo and endometrium, and the role of extracellular vesicles (EVs) in facilitating this cross-talk has been recently established. In our previous study, milk fat globule-EGF factor 8 protein (MFGE8) was identified as increasing in receptive endometrial epithelial cells (EECs) in response to trophoblastic EVs. However, the dynamics of MFGE8 protein in this context are not completely understood. Therefore, we examined its expression and secretion in EECs exposed to estrogen, progesterone, and trophoblastic EVs to gain deeper insights into its potential as an indicator of EV-mediated embryo-maternal dialogue. Our findings revealed that MFGE8 secretion is sensitive to estrogen and progesterone, and that trophoblastic EVs stimulate their release in both receptive and non-receptive EECs. Furthermore, trophoblast EV function was dose and time-dependent. Notably, the secretion of MFGE8 increased within a short timeframe of 30 min after addition of EVs, suggesting the possibility of rapid processes such as binding, fusion or internalization of trophoblastic EVs within EECs. Interestingly, MFGE8 released from EECs was associated with EVs, suggesting increased EV secretion from EECs in response to embryonic signals. In conclusion, increased MFGE8 secretion in this embryo implantation model can serve as an indicator of EV-mediated embryo-maternal dialogue., (© 2024. The Author(s).)

To evaluate whether RNA-seq-based endometrial receptivity testing (rsERT) can improve pregnancy outcomes in personalized frozen-thawed embryo transfer (pFET) during hormone replacement therapy (HRT) cycles among patients with recurrent implantation failure (RIF). We conducted a retrospective cohort study involving 98 RIF patients undergoing HRT for FET. The experimental group consisted of 58 patients who underwent pFET after rsERT, while the control group included 40 patients who refused rsERT and underwent conventional ET. We recorded and examined the subsequent pregnancy outcomes from all cycles. The results of rsERT revealed that 67.24% of the experimental group were out of the "window of implantation" (WOI), with all cases showing a delay. The HCG-positive rate, implantation rate, and clinical pregnancy rate (CPR) in the experimental group were significantly higher than those in the control group, at 75.86% versus 50.00% (P = .030), 56.38% versus 31.43% (P = .002), and 68.97% versus 47.50% (P = .033), respectively. Our study demonstrated that utilizing rsERT technology to guide pFET in HRT cycles significantly enhances implantation and CPRs in RIF patients. Importantly, our findings confirm the effectiveness of rsERT technology and establish a scientific rationale for personalized reproductive medical interventions., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

This study aimed to investigate the expression and functional role of nesfatin-1, a peptide hormone traditionally associated with appetite regulation, in the human endometrium. Specifically, we examined its presence and regulatory potential in the human endometrial stromal cell line, THESC cells, focusing on the process of endometrial decidualization, which is critical for implantation and pregnancy maintenance. We found that nesfatin-1 and its binding sites were expressed in THESC cells. Furthermore, nesfatin-1 protein expression decreased after treatment with 17β-estradiol but increased upon exposure to progesterone, indicating an influence of sexsteroid hormones on nesfatin-1 expression. Notably, administration of nesfatin-1 protein to THESC cells resulted in significant upregulation of genes associated with decidualization, such as insulin-like growth factor binding protein 1 (IGFBP1) and prolactin. In addition, our research showed that nesfatin-1 promotes decidualization through the activation of the FAK/PI3K/AKT signaling pathway. These findings underscore the central role of nesfatin-1 in endometrial decidualization, and suggest its potential utility in the development of new treatments to improve fertility and pregnancy outcomes., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Hyunwon Yang reports administrative support, article publishing charges, equipment, drugs, or supplies, statistical analysis, travel, and writing assistance were provided by Seoul Women’s University. Hyunwon Yang reports a relationship with Seoul Women’s University that includes: employment. Hyunwon Yang has patent None pending to None. I declare that there is no conflict of interest regarding the publication of this manuscript. The research was conducted without any influence or support from external organizations or entities that could bias the results or interpretation of the findings. No financial, personal, or professional relationships that could be perceived as having influenced the research or conclusions have been involved. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The GATA gene family encodes highly conserved zinc-finger transcription factors that facilitate the development and function of multiple organ systems including the uterus. In the endometrium, GATA2 functions in a positive autoregulatory loop with the progesterone receptor (PGR) and colocalizes with PGR on chromatin to promote PGR transcriptional programs. GATA2 also has PGR-independent functions that maintain endometrial cell identity, and GATA2 transcripts reportedly are down-regulated in endometrial disorders including endometriosis. This event is accompanied by a reciprocal increase in GATA6. Here, we applied custom anti-GATA2 monoclonal antibodies and performed GATA2 immunohistochemistry (IHC) on patient endometrial tissues corresponding to proliferative, secretory, inactive, and hormone-treated endometrium, as well as endometriosis and endometrial atypical hyperplasia/endometrioid intraepithelial neoplasia (EAH/EIN). We also performed IHC for the estrogen receptor, PGR, and GATA6 in relevant groups. The results reveal a tight correlation between GATA2 and PGR expression in the glandular and stromal cells of benign endometrium. GATA2 expression is markedly reduced in stromal but not glandular cells in endometriosis and EAH/EIN. This reduction in GATA2 expression does not lead to a detectable increase in GATA6 expression in endometriosis. Although average glandular GATA2 expression was preserved in endometriosis and EAH/EIN cases, its expression was decoupled from PGR, implying that alternative pathways regulate GATA2 levels in these disorders. Our findings indicate that GATA2 dysregulation is a feature of endometriosis and EAH/EIN, and support a model whereby loss of stromal GATA2 in these disorders contributes to their progesterone insensitivity., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

A reduction in myometrial contractile activity can lead to inadequate cleaning of the uterine lumen, resulting in persistent endometritis and potentially endometrosis in mares. Oxytocin (OXT) is a key hormonal regulator of myometrial contraction. While epigenetic regulation of myometrial gene expression has been studied in humans, there is limited information on the expression of DNA methyltransferases (DNMTs) and ten-eleven translocation enzymes (TETs) in the myometrium of mares. This study aimed to evaluate the mRNA transcription of these enzymes and the potential role of DNA methylation in the expression of the OXT receptor (OXTR) gene in the myometrium of mares with endometrosis. Myometrial samples were collected post-mortem during the mid-luteal (n = 23) and follicular (n = 20) phases of the estrous cycle and assessed according to Kenney and Doig endometrial category (I, IIA, IIB, III). mRNA transcription of OXTR, DNMT1, -3A, -3B and TET1, -2, -3 were determined using qPCR. DNA methylation analysis at CpG islands of OXTR exons 1 and 2 was performed using bisulfite pyrosequencing. Myometrial OXTR mRNA transcription and DNA methylation in its promoter region showed no significant differences between categories, although increased methylation was observed at CpG island position 6 in exon 2. DNMT1, TET2, and TET3 mRNA transcription was altered in the equine myometrium depending on the phase of the estrous cycle and the severity of endometrosis (P < 0.05). These findings indicate that DNMTs and TETs were expressed in myometrium in a manner specific to the severity of endometrosis and phases of the estrous cycle, suggesting a potential regulatory role in DNA methylation of myometrial gene expression., Competing Interests: Declaration of Competing Interest No., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Humans were long thought to be the only mammal to experience menopause, the permanent cessation of reproduction followed by a long post-reproductive lifespan. More recently, evidence has been found for the existence of menopause in other long-lived mammals, including chimpanzees and gorillas. However, orangutans, which have the longest interbirth interval of any primate, have rarely been studied in this period of their lives. In this paper, we describe clinical, ultrasound, endocrine, and histological evidence consistent with a natural menopause in a captive, previously fertile, Sumatran orangutan (Pongo abelii), aged approximately 50. Consecutive serum samples showed low levels of estradiol and high levels of follicle-stimulating hormone. Transvaginal ultrasound revealed an atrophic uterus with an antero-posterior diameter of 2.36 cm, an endometrial thickness of 2 mm, and inactive ovaries. Following this female's death from a subdural hematoma, histological examination of the ovaries showed a dense stroma with corpora albicantia, in comparison to the numerous primordial follicles seen in the ovaries of a stillborn infant female orangutan. These multiple lines of evidence suggest that Sumatran orangutans can now be added to the list of mammals which undergo a true menopause, which may ensure that females' final offspring can be reared to independence., (© 2024 Wiley Periodicals LLC.)

Chronic endometritis (CE) is a persistent inflammation of the endometrium caused by microbial infection, which is characterized by the infiltration of plasma cells into the endometrial stromal area. CE emerges as a critical determinant in the etiology of female infertility and is closely associated with adverse pregnancy outcomes, such as recurrent spontaneous abortion and repeated implantation failure, imposing a heavy burden on patients and their families. However, current understanding of CE-induced infertility remains superficial, leading to delays and inconsistent approaches in the diagnosis and treatment of the condition. Emphasizing the diagnosis and treatment of CE can help improve women's reproductive health, alleviate the economic and psychological pressures of patients and their families, resolve family conflicts and promote family and social harmony. This article provides an in-depth analysis of the diagnostic criteria and current application status of CE, its impact on endometrial receptivity and fallopian tubal function, as well as its interplay with other gynecological disorders. In alignment with clinical practice, we propose suggestions including enhancing the understanding of CE, strengthening publicity and education, standardizing the diagnostic process for CE, exploring the molecular mechanisms of CE and optimizing treatment strategies, in order to improve the comprehensive diagnosis and treatment strategies of CE-induced infertility and make greater contributions to the reproductive health of women in China.

Chronic endometritis (CE) is an important factor leading to decreased endometrial receptivity, infertility, and repeated pregnancy loss; endometrial immune dysfunction, abnormal microbial flora, inflammatory status, and other factors play important roles in the occurrence and development of CE. Meanwhile, these factors are closely related to the pathophysiological mechanisms of common diseases that cause infertility, such as endometriosis, polycystic ovary syndrome, tubal diseases, and endometrial polyps. Through further development of high-quality prospective clinical research, microbiome and immunomics of CE and endometriosis,polycystic ovary syndrome and other diseases, to provide a new therapeutic idea for the treatment of refractory CE. In the course of clinical practice, the effective integration of the diagnosis and treatment principles of CE concomitant diseases in the treatment of CE is expected to provide a new choice for preventing the recurrence of CE.

The loss of a cyclic change with two peaks of increased endometrial epidermal growth factor (EGF) concentration on days 2-4 and 13-14 during the estrous cycle has been linked to low fertility in repeat breeder (RB) cows. We have shown that an intravaginal infusion of osteopontin (OPN) restored the EGF profile in RB cows. The present study aimed to determine a structural element of OPN to restore the normal EGF profile and fertility. Holstein RB cows were diagnosed the EGF profile by a single examination of the endometrial EGF concentration on day 3 of the estrous cycle. Those with an altered EGF profile were intravaginally infused with OPN and its fragments on the day of insemination (day 0); the concentration of endometrial EGF was measured on day 3, and pregnancy was diagnosed on days 30-35. In Study 1, recombinant OPN (rOPN) (16 nmol), thrombin-cleaved N- and C-terminal fragments of rOPN (N-rOPN and C-rOPN, respectively), and a combination of these fragments (Th-rOPN) were infused (n = 13-20). The restoration rate of the normal EGF profile of the N-rOPN group (25.0 %) was a level in between the C-rOPN group (7.7 %) and both the rOPN (55.6 %) and Th-rOPN (64.3 %) groups. In Study 2, PBS (n = 47), rOPN (9.5 nmol, n = 83), and peptides of integrin binding motifs, GRGDSVAYGLK (peptide 1; 32, 320, and 1600 nmol), GRGDS (peptide 2; 320 and 1600 nmol), and SVAYGLK (peptide 3; 320 and 1600 nmol), were infused (n = 20-25). Restoration rates of the normal EGF profile of peptide 1 (320 and 1600 nmol) and peptide 3 (1600 nmol) groups (44.0-56.3 %) were comparable with those of the rOPN group (63.9 %) and higher than those of the PBS group (15.6 %). Restoration rates of the other groups were similar to those of the PBS group. Additional cows received infusions to determine the effect on fertility. Conception rates of the peptide 1 (320 and 1600 nmol; n = 50 each), peptide 3 (1600 nmol; n = 55), and rOPN (n = 111) groups (41.8-50.0 %) were comparable and higher than that of the PBS group (21.6 %, n = 75). In Study 3, PBS (n = 24), peptide 1 (320 nmol; n = 78), and GRGESVAYGLK peptide (peptide 4; 320 and 1600 nmol; n = 50 and 26, respectively) were infused. Restoration rates of the normal EGF profile of peptide 4 and PBS groups (16.0-19.2 %) were comparable and lower than those of the peptide 1 group (44.9 %). Thus, the SVAYGLK motif may be an OPN structural element to restore the normal EGF profile and fertility in RB cows, and the RGD motif may enhance its effect., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Recent literature has explored the role of human chorionic gonadotropin (hCG) triggering in frozen embryo transfer (FET) cycles with natural endometrial preparation. Despite this, the impact of hCG triggering on pregnancy outcomes following endometrial preparation with mild stimulation (mST) using Letrozole and Gonadotropins remains inadequately characterized. This study aimed to elucidate the effects of hCG-trigger on pregnancy outcomes in mST-FET cycles., Methods: In the present retrospective cohort study, the pregnancy outcomes of 409 eligible patients who underwent FET cycles with endometrial preparation using a mild ovarian stimulation protocol by letrozole plus low dose gonadotropins at the Royan Institute between 2020 and 2022, were investigated. The study population were segregated into two distinct groups according to type of ovulation: the spontaneous ovulation group (n = 138) and the hCG-trigger group (n = 271). The pregnancy outcomes including implantation and clinical pregnancy rates (CPR) and live birth rates (LBR) were compared between two groups. The multivariable logistic regression was performed to detect the most significant variables related to the LBR in the mST-FET cycles., Results: Demographic and baseline characteristics were comparable between groups. No significant difference was found in terms of implantation rate (0.65 ± 0.32 vs. 0.60 ± 0.30, P-value: 0.31), CPR (37% vs. 39.7%, P-value: 0.53), and LBR (35.5% vs. 37.3%, P-value: 0.74) in the spontaneous ovulation and hCG-trigger groups, respectively. The logistic regression analysis revealed that only the stage of the transferred embryo exhibited a significant relationship with LBR (blastocyst vs. cleavage: odds ratio (OR); 2.33, 95% confidence interval (CI):1.41-3.86, P-value = 0.001)., Conclusion: Pregnancy outcomes in the mST-FET cycles, including implantation rate, CPR, and LBR are comparable in cycles with or without hCG triggering. Based on the findings from multivariate regression analysis, the sole significant predictive factor for the LBR was the transfer of blastocyst embryos. It is recommended that these results be examined and discussed in future prospective studies with a larger sample size, considering the lack of comparable research in this field., (© 2024. The Author(s).)

Fatty acids (FAs) are important for cell membrane composition, eicosanoid synthesis, and metabolic processes. Membrane proteins that facilitate FA transport into cells include FA translocase (also known as CD36) and FA transporter proteins (encoded by SLC27A genes). The present study aimed to examine expression profiles of FA transporters in the endometrium of cyclic and early pregnant gilts on days 3 to 20 after estrus and the possible regulation by conceptus signals and polyunsaturated FAs (PUFAs). The effect of PUFAs on prostaglandin (PG) synthesis and transcript abundance of genes related to FA action and metabolism, angiogenesis, and immune response was also determined. Day after estrus and reproductive status of animals affected FA transporter expression, with greater levels of CD36, SLC27A1, and SLC27A4 observed in pregnant than in cyclic gilts. Conceptus-conditioned medium and/or estradiol-17β stimulated SLC27A1 and CD36 expression. Among PUFAs, linoleic acid decreased SLC27A1 and SLC27A6 mRNA expression, while arachidonic, docosahexaenoic, and eicosapentaenoic acids increased SLC27A4 transcript abundance. Moreover, arachidonic acid stimulated ACOX1 , CPT1A , and IL1B expression and increased PGE2 and PGI2 secretion. In turn, α-linolenic acid up-regulated VEGFA, FGF2, FABP4, and PPARG mRNA expression. These results indicate the presence of an active transport of FAs in the porcine endometrium and the role of PUFAs as modulators of the uterine activity during conceptus implantation.

Objective: To investigate if a positive result on ReceptivaDx for evaluation of B-cell lymphoma 6 (BCL6), a proposed marker of progesterone resistance associated with impaired uterine receptivity, correlates with a suboptimal profile of receptivity-associated markers in the window of implantation using the endometrial receptivity array and single-nucleus transcriptomic analysis DESIGN: Retrospective clinical cohort study; pilot study of single-nucleus RNA sequencing of prospectively collected window of implantation endometrium undergoing ReceptivaDx BCL6 evaluation SETTING: Academic center SUBJECTS: Patients with infertility who underwent endometrial biopsy for concurrent endometrial receptivity array analysis (ERA®; Igenomix) and BCL6 immunostaining (ReceptivaDx™; Cicero Diagnostics, Inc.) EXPOSURE: Positive BCL6 result on ReceptivaDx™ (histologic score 'HSCORE' >1.4) MAIN OUTCOME MEASURES: Pre-receptive ERA result; relative expression levels of endometrial receptivity-associated epithelial genes by single-nucleus sequencing RESULTS: One hundred and seventy-two patients with concurrent ERA and ReceptivaDx evaluation were included in the analysis: 40 were BCL6-positive and 132 were BCL6-negative. One patient (2.5%) in the BCL6-positive group had a pre-receptive ERA result, compared to 29 patients (22.0%) in the BCL6-negative group (p<0.01). BCL6 positivity was associated with decreased odds of a pre-receptive ERA result (OR 0.09 95%CI [0.01-0.69], p=0.02). Single-nucleus transcriptomic analysis of 5,718 epithelial cell nuclei from four individuals showed significant cell type-specific transcriptomic changes associated with a positive ReceptivaDx BCL6 result in both natural cycle (NC) and programmed cycle (PC) endometrium: there were 2,801 significantly differentially expressed genes (DEGs) comparing NC BCL6-positive to -negative, and 1,062 DEGs comparing PC BCL6-positive to -negative. Of the 34 receptivity-associated epithelial markers evaluated, 16 were significantly upregulated in NC BCL6-positive versus -negative endometrium epithelial nuclei. In PC epithelial nuclei, 12 of the 34 receptivity-associated genes were significantly upregulated, while only 1 was significantly downregulated in BCL6-positive versus -negative endometrium., Conclusions: A positive ReceptivaDx BCL6 result does not correlate with a pre-receptive ERA. Epithelial cells from BCL6-positive endometrium did not show significantly decreased expression in most of the receptivity markers evaluated. These findings demonstrate discordance between the interpretation of "endometrial receptivity" by ReceptivaDx and ERA, and highlight the need for further validation of endometrial evaluation methods in fertility treatment., (Copyright © 2024. Published by Elsevier Inc.)

Context: Obesity is a disease with deleterious effects on the female reproductive tract, including the endometrium., Objective: We sought to understand the effects of excess adipose on the benign endometrium., Methods: A physiologic in vitro coculture system was developed, consisting of multicellular human endometrial organoids, adipose spheroids, and menstrual cycle hormones. Native human endometrial tissue samples from women with and without obesity were also analyzed. Benign endometrial tissues from premenopausal women ages 33 to 53 undergoing hysterectomy were obtained following written consent at Northwestern University Prentice Women's Hospital, Chicago, Illinois. Gene expression, protein expression, chromatin binding, and expression of DNA damage and oxidative damage markers were measured., Results: Under high adiposity conditions, endometrial organoids downregulated endometrial secretory phase genes, suggestive of an altered progesterone response. Progesterone specifically upregulated the metallothionein (MT) gene family in the epithelial cells of endometrial organoids, while high adiposity significantly downregulated the MT genes. Silencing MT genes in endometrial epithelial cells resulted in increased DNA damage, illustrating the protective role of MTs. Native endometrium from women with obesity displayed increased MT expression and oxidative damage in the stroma and not in the epithelium, indicating the cell-specific impact of obesity on MT genes., Conclusion: Taken together, the in vitro and in vivo systems used here revealed that high adiposity or obesity can alter MT expression by decreasing progesterone response in the epithelial cells and increasing oxidative stress in the stroma., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Conceptus estrogens and prostaglandins have long been considered the primary signals for maternal recognition of pregnancy (MRP) in the pig. However, loss-of-function studies targeting conceptus aromatase genes (CYP19A1 and CYP19A2) and prostaglandin-endoperoxide synthase 2 (PTGS2) indicated that conceptuses can not only signal MRP without estrogens or prostaglandins but can maintain early pregnancy. However, complete loss of estrogen production leads to abortion after day 25 of gestation. Although neither conceptus estrogens nor prostaglandins had a significant effect on early maintenance of corpora lutea (CL) function alone, the two conceptus factors have a biological relationship. To investigate the role that both conceptus estrogens and prostaglandins have on MRP and maintenance of pregnancy, a triple loss-of function model (TKO) was generated for conceptus CYP19A1, CYP19A2, and PTGS2. In addition, a conceptus CYP19A2-/- model (A2KO) was established to determine the role of placental estrogen during later pregnancy. Estrogen and prostaglandin synthesis were greatly reduced in TKO concept uses which resulted in a failure to inhibit luteolysis after day 15 of pregnancy despite the presence of conceptuses in the uterine lumen. However, A2KO placentae not only maintained functional CL but were able to maintain pregnancy to day 32 of gestation. Despite the loss of placental CYP19A2 expression, the allantois fluid content of estrogen was not affected as the placenta compensated by expressing CYP19A1 and CYP19A3, which are normally absent in controls. Results suggest conceptuses can signal MRP through production of conceptus PGE or stimulating PGE synthesis from the endometrium through conceptus estrogen. Failure of conceptuses to produce both factors results in failure of MRP and loss of pregnancy., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The first interactions among the embryo, endometrium, and corpus luteum (CL) are essential for pregnancy success. Small extracellular vesicles (sEVs) are part of these interactions. We previously demonstrated that sEVs from in vivo- or in vitro-produced bovine embryos contain different miRNA cargos. Herein we show: 1) the presence and origin (in vivo or in vitro) of the blastocyst differentially reprograms endometrial transcriptional profiles; 2) the endometrial explant (EE) cultured with in vivo or in vitro embryos release sEVs with different miRNA contents, and; 3) the luteal explant (CLE) exposed to these sEVs have distinct mRNA and miRNA profiles. To elucidate this, the EE were cultured in the presence or absence of a single Day-7 in vivo (EE-AI) or in vitro (EE-IVF) embryo. After of culture we found, in the EE, 45 and 211 differentially expressed genes (DEGs) associated with embryo presence and origin, respectively. SEVs were recovered from the conditioned media (CM) in which EE and embryos were co-cultured. Four miRNAs were differentially expressed between sEVs from CM-EE-AI and CM-EE-IVF. Luteal explants exposed in culture to these sEVs showed 1360 transcripts, and fifteen miRNAs differentially expressed. The DEGs associated with embryo presence and origin, modulating cells' proliferation, and survival. These results demonstrate that in vivo- or in vitro-produced bovine embryos induce molecular alterations in the endometrium; and that the embryo and endometrium release sEVs capable of modifying the mRNA and miRNA profile in the CL. Therefore, the sEVs-mediated embryo-endometrium-CL interactions possibly regulate the CL viability to ensure pregnancy success., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Competing Interests: Competing interests: None declared.

Background: The 2023 International Federation of Gynecology and Obstetrics (FIGO) staging system includes lymphovascular invasion quantification as a staging criterion for endometrioid endometrial carcinomas; no lymphovascular invasion and focal invasion (≤4 vessels involved) are grouped as one category, and substantial invasion as another., Objective: To assess the association between lymphovascular invasion and oncologic outcomes., Methods: We retrospectively identified patients with FIGO 2009 stage I endometrioid endometrial cancer treated surgically with total hysterectomy and lymph node assessment at two tertiary care centers between January 1, 2012, and December 31, 2019. Lymphovascular space invasion was categorized as focal (<5 vessels involved), substantial (≥5 vessels involved), and no lymphovascular invasion using WHO criteria., Results: Of 1555 patients included, 65 (4.2%) had substantial, 119 (7.7%) had focal, and 1371 (88.2%) had no lymphovascular invasion. Median age was 64 years (range 24-92). Thirty-five patients (53.8%) with substantial, 44 (37%) with focal, and 115 (8.4%) with no lymphovascular invasion had stage IB disease (p<0.001); 21 (32.3%) with substantial, 24 (20.2%) with focal, and 91 (6.6%) with no lymphovascular invasion had grade 3 disease (p<0.001). Thirty-six patients (55.4%) with substantial, 80 (67.2%) with focal, and 207 (15.1%) with no lymphovascular invasion received adjuvant treatment (p<0.001). Median follow-up was 61.5 months (range 0.8-133.9). Five-year progression-free survival rates were 68.7% (substantial), 70.5% (focal), and 90.7% (no invasion) (p<0.001). On multivariate analysis, any lymphovascular invasion was associated with increased risk of progression/death (adjusted HR (aHR)=1.84 (95% CI 1.73 to 1.96) for focal; 2.17 (95% CI 1.96 to 2.39) for substantial). Compared with focal, substantial lymphovascular invasion was associated with an aHR for disease progression of 1.18 (95% CI 1.00 to 1.39)., Conclusions: Focal and substantial lymphovascular invasion were associated with increased risk of disease progression and do not appear to be prognostically distinct. Focal versus no lymphovascular invasion have different prognostic outcomes and should not be combined into one category., Competing Interests: Competing interests: AGE reports speakers fee from Intuitive Surgical and GSK. BD is a speaker and consultant for MSD. NRA-R reports research funding from GRAIL paid to the institution. ML reports personal fees from Medtronic, Intuitive Surgical, J&J/Ethicon, and Immunogen. VM is supported (all funding to institution)/unpaid consultancy/advisory board membership from AstraZeneca, Clovis, Duality, Eisai, Faeth, Genentech, GSK, Immunocore, iTEOS, Kartos, Karyopharm, Moreo, Morphosys, MSD, Novartis, Takeda, and Zymeworks. The other authors have nothing to disclose., (© IGCS and ESGO 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To assess the distribution of molecular classes and their impact on the risk of recurrence in endometrial cancer patients with lymph node metastasis at the time of primary surgery., Methods: Endometrial cancer patients with lymph node micrometastasis or macrometastasis (International Federation of Gynecology and Obstetrics (FIGO) 2009 stage IIIC) after surgical staging at five referral centers worldwide from October 2013 to September 2022 who underwent molecular classification were identified. Endometrial cancers were categorized into four molecular classes: POLE mutated, mismatch repair deficient, p53 abnormal, and no specific molecular profile. Survival analyses using Kaplan-Meier and Cox models (univariate and multivariate) were conducted to evaluate the relationship between molecular class and 5-year recurrence free survival., Results: 131 patients were included: 55 (42.0%) no specific molecular profile, 46 (35.1%) mismatch repair deficient, 1 (0.8%) POLE mutated, and 29 (22.1%) p53 abnormal. During a 5 year follow-up period, 50 (38.2%) patients experienced a recurrence with a median time of 1.2 years (interquartile range (IQR) 0.5-1.8). Median follow-up for the remaining 81 patients was 3.1 years (IQR 1.3-4.5). Survival analysis revealed a significant difference in recurrence-free survival between no specific molecular profile, mismatch repair deficient, and p53 abnormal classes (log rank p<0.01). In a model adjusted for type of lymph node metastasis and tumor grade, the molecular class did not retain significance (p=0.13), while in a model adjusted for type of lymph node metastasis and adjuvant therapy, the molecular class retained significance (p<0.01)., Conclusion: Among patients with stage IIIC endometrial cancer, POLE mutated tumors exhibited an extremely low prevalence, with no specific molecular profile emerging as the largest molecular subgroup. Despite the significant difference in recurrence-free survival between molecular classes, conventional histopathologic parameters retained crucial prognostic value. Our findings highlight the necessity of integrating molecular classes with pathological characteristics, rather than considering them in isolation as crucial prognostic factors in stage IIIC endometrial cancer., Competing Interests: Competing interests: None declared., (© IGCS and ESGO 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

The aim of this study was to identify differentially expressed lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) in the endometrium of individuals with and without endometriosis (EMS) during the proliferative (P) and secretory (S) phases of the menstrual cycle. Tissues were obtained from 18 control (CT; P-phase [pCT], n = 8; S-phase [sCT], n = 13) and 23 EMS patients (P-phase [pEMS], n = 13; S-phase [sEMS], n = 12). DElncRNAs and DEmRNAs were analyzed using total RNA-sequencing. In P-phase, expression of NONHSAG019742.2 and NONHSAT120701.2 was significantly higher in EMS than control patients, that of while NONHSAG048398.2 and NONHSAG016560.2 was lower in EMS patients. In S-phase, expression of NONHSAT000959.2 , NONHSAT203423.1 , and NONHSAG053769.2 was significantly increased in EMS patients, while that of NONHSAG012105.2 and NONHSAG020839.2 was lower. In addition, the expression of HSD11B2 , THBS1 , GPX3 , and SHISA6 was similar to that of neighboring lncRNAs in both P- and S-phases. In contrast, ELP3 and NR4A1 , respectively, were up- or downregulated in pEMS tissues. In sEMS, expression of LAMB3 and HIF1A was increased, while expression of PAM was reduced. Our findings on lncRNAs and mRNAs encourage not only exploration of the potential clinical applications of lncRNAs and mRNAs as prognostic or diagnostic biomarkers for EMS but also to gain valuable insights into its pathogenesis.

Background: Cervical squamous cell carcinoma (SCC) is the most common type of cervical carcinoma. Usually, the cancer metastasizes through lymphatic or hematogenous dissemination. However, it is uncommon for a superficial spreading of cervical cancer to reach the endometrium, fallopian tubes, and the ovaries., Objectives: In the present study, we report 15 cases of superficial spreading SCC and discuss the possible mechanism involved., Methods: We collected 15 samples diagnosed by histopathology after surgery. Immunostaining, which included P16, P63, CD138, CD34, D2-40, and Ki-67, were performed for all samples., Results: All patients were postmenopausal or perimenopausal women. The commonest clinical presentation was vaginal bleeding in 66.67%. All patients were infected with HPV 16. The endometrium was replaced by high-grade squamous intraepithelial lesion (HSIL), which involved the endometrial gland, even squeezing into the myometrium and forming SCC. Bilateral fallopian tubes and ovaries involvement was in 1/15. A total of 10/15 (66.67%) of the women had disease of stage 1B or less. All SCCs were moderately or poorly differentiated. Immunohistochemistry revealed that the tumor cells were positive for P63 and P16, with a high Ki-67 labeling index. There was CD138 positive expression in varying degrees, which was strongly and diffusely expressed in 6/15 (40.00%)., Conclusion: Superficial spread of cervical cancer towards the endometrium is a rare but cognizable phenomenon, and a guideline for the management of these cases has not been established. Our present findings suggest that multiple factors may interact with each other simultaneously, contributing to this rare disease., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Jiang, Han, Chun, Wen and Chen.)

Increased synthesis and deposition of collagen (COL) in the extracellular matrix (ECM) of equine endometrium contributes to endometrosis. Toll-like receptors (TLRs) are transmembrane receptors involved in the innate immune response, recognized for their role in antigen recognition and previously associated with equine endometritis. The TLRs not only recognize pathogen-associated molecular patterns but also regulate inflammations, fibrosis and cancer. The aim of this study was to explore the relationship between TLR expression at different stages of Kenney and Doig's (K-D) grading and COL1 expression during the follicular phase of the oestrous cycle. Forty samples of endometrial tissues were collected post-mortem from mares on the follicular phase of the oestrous cycle (10 samples of each K-D category). Relative mRNA transcription of TLR-2, TLR-4 and COL1A2 genes was assessed using qPCR, and COL1 protein expression by Western blot analysis. The COL1A2 transcription increased in category IIB when compared to categories I, IIA and III endometria (p < .01). The relative protein abundance of COL1 showed no significant differences between endometrial categories (p > .05). As for the TLRs mRNA transcription, TLR-2/-4 transcripts increased in IIA when compared to the other K-D endometria categories (p < .05). Our findings suggest that TLRs may be involved in the initiation of the endometrial inflammatory response. Additional studies are needed to explore TLRs' potential role as diagnostic markers for monitoring inflammation progression and fibrosis development, as well as their involvement in the mechanisms underlying fibrotic pathways., (© 2024 Wiley‐VCH GmbH. Published by John Wiley & Sons Ltd.)

Purpose: To investigate whether personalized embryo transfer (pET) predicted by a modified RNA-sequencing-based endometrial receptivity test (rsERT) model can improve intrauterine pregnancy rate (IPR) in patients with a receptive window of implantation (WOI)., Design: A retrospective pilot study was conducted in the Center for Reproductive Medicine, Central South University, from January 2018 to December 2023. A total of 524 patients with receptive WOI results from rsERT were assigned into two groups based on whether they underwent conventional embryo transfer (conventional ET) or pET. Patients in the conventional ET were matched with those in the pET group at a 1:1 ratio using propensity score matching (PSM)., Results: Before PSM, the IPR (55.73% vs. 46.19%, P = 0.032) and implantation rate (IR) (47.51% vs. 34.03%, P = 0.000) in the pET group were significantly higher than that in the conventional ET group. However, the number and types of transferred embryos differed significantly between the two groups. After adjusting for confounding factors, IPR (57.38% vs. 44.81, P = 0.016) and IR (46.81% vs. 33.10%, P = 0.001) remained significantly higher in the pET group compared to the conventional ET group. The implantation failure rate was significantly lower in the pET group compared to controls (42.62% vs. 55.19%, P = 0.016). Additionally, the multiple-pregnancy rate was significantly higher in the pET group compared to the conventional ET group (10.29% vs. 1.68%, P = 0.001)., Conclusions: Women with receptive WOI results could benefit from the receptivity-timed pET predicted by the newly refined rsERT. These findings provide a basis for future research in precision medicine for embryo transfer., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objectives: To transform the standardized descriptions of the ultrasound characteristics of endometrial and intrauterine lesions devised by the International Endometrial Tumor Analysis (IETA) group into a practical scoring method and to investigate whether application of this method enhances the diagnostic accuracy of ultrasound radiologists with different levels of experience in detecting malignancy compared with subjective assessment., Methods: This was a retrospective study of 855 patients with endometrial and/or intrauterine lesions, who were divided into a training (n = 600) and a validation (n = 255) set. Ultrasound radiologists with varying levels of experience (expert, intermediate and junior) evaluated all lesions by subjective assessment and according to IETA rules. Using IETA rules, the experts identified signs of malignancy in the training set, assigned scores for each indicator and validated the scoring method in the validation set. The intermediate-level and junior ultrasound radiologists reassessed the malignancy of the lesions using the IETA scoring method and compared their classifications with those made previously by subjective assessment. Postsurgical pathological evaluation was used as the reference standard., Results: Using subjective assessment, the experts demonstrated the highest level of diagnostic accuracy, with a sensitivity of 85.0%, specificity of 94.3% and an area under the receiver-operating-characteristics curve (AUC) of 0.897. Applying the IETA scoring method (comprising eight ultrasound characteristics that contributed to the total score) with a threshold of > 25 points for the diagnosis of malignancy achieved a sensitivity of 84.7%, specificity of 94.7% and AUC of 0.9533 in the training set, with similar performance in the validation set, when performed by experts. Using the IETA scoring method, both junior and intermediate ultrasound radiologists showed improvement in sensitivity (from 55.5% to 74.8% and from 70.2% to 77.1%, respectively), specificity (from 88.4% to 91.5% and from 87.4% to 92.2%, respectively) and AUC (from 0.704 to 0.827 and from 0.793 to 0.841, respectively) for diagnosing malignant lesions., Conclusions: The IETA scoring method exhibits high diagnostic efficacy for malignant endometrial and intrauterine lesions. This method compensates for the lack of experience among junior and intermediate-level ultrasound radiologists, enhancing their diagnostic skill to a level nearing that of experienced senior ultrasound radiologists. Further research is essential to validate the practicality of implementing this method and to confirm its clinical value. © 2024 International Society of Ultrasound in Obstetrics and Gynecology., (© 2024 International Society of Ultrasound in Obstetrics and Gynecology.)

Human reproductive success relies on the proper differentiation of the uterine endometrium to facilitate implantation, formation of the placenta, and pregnancy. This process involves two critical types of decidual uterine cells: endometrial/decidual stromal cells (dS) and uterine/decidual natural killer (dNK) cells. To better understand the transcription factors governing the in vivo functions of these cells, we analyzed single-cell transcriptomics data from first-trimester terminations of pregnancy, and for the first time conducted gene regulatory network analysis of dS and dNK cell subpopulations. Our analysis revealed stromal cell populations that corresponded to previously described in vitro decidualized cells and senescent decidual cells. We discovered new decidualization driving transcription factors of stromal cells for early pregnancy, including DDIT3 and BRF2, which regulate oxidative stress protection. For dNK cells, we identified transcription factors involved in the immunotolerant (dNK1) subpopulation, including IRX3 and RELB, which repress the NFKB pathway. In contrast, for the less immunotolerant (dNK3) population we predicted TBX21 (T-bet) and IRF2-mediated upregulation of the interferon pathway. To determine the clinical relevance of our findings, we tested the overrepresentation of the predicted transcription factors target genes among cell type-specific regulated genes from pregnancy disorders, such as recurrent pregnancy loss and preeclampsia. We observed that the predicted decidualized stromal and dNK1-specific transcription factor target genes were enriched with the genes downregulated in pregnancy disorders, whereas the predicted dNK3-specific targets were enriched with genes upregulated in pregnancy disorders. Our findings emphasize the importance of stress tolerance pathways in stromal cell decidualization and immunotolerance promoting regulators in dNK differentiation., (© 2024. The Author(s).)

Research Question: Does the application of a micro-dose of copper chloride gel increase endometrial production of vascular endothelial growth factor (VEGF) without compromising endometrial function or producing embryo toxicity?, Design: An estimate of optimal dose was made based on cell culture studies. Ten healthy participants received an initial uterine application of placebo gel, followed by copper chloride gel (37.5 μM, 75 μM, or 150 μM dose) in a later hormone replacement cycle. Endometrial biopsies (day 5.5 luteal) and pelvic ultrasound were carried out during each cycle to evaluate endometrial function and growth. Uterine fluid was assessed for residual copper levels on the day of biopsy, and copper chloride gel underwent mouse embryos assay assessment for potential embryo toxicity., Results: The copper gel significantly increased endometrial VEGF expression (quantitative polymerase chain reaction), and also increasing endometrial thickness by an average of 2.2 mm compared with matched control cycles. The copper gel did not adversely affect endometrial morphology or maturation (histological dating and molecular receptivity testing), and mouse embryos assay studies showed no evidence of embryo toxicity. Furthermore, uterine cavity flush samples mostly lacked copper, with only negligible amounts present in one sample., Conclusion: Applying copper chloride gel to the uterine cavity upregulated endometrial VEGF and significantly increased endometrial thickness and volume. No adverse effects on the endometrium or embryos were observed. Copper chloride gels show promise for treating suboptimal endometrial thickness if the results of this study are confirmed by larger randomized controlled trials., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Reproductive failure due to age, genetics and disease necessitates innovative solutions. While reproductive tissue transplantation has advanced, ongoing research seeks superior approaches. Biomaterials, bioengineering and additive manufacturing, such as three-dimensional (3D) bioprinting, are harnessed to restore reproductive function. 3D bioprinting uses materials, cells and growth factors to mimic natural tissues, proving popular for tissue engineering, notably in complex scaffold creation with cell distribution. The versatility which is brought to reproductive medicine by 3D bioprinting allows more accurate and on-site applicability to various problems that are encountered in the field. However, in the literature, there is a lack of studies encompassing the valuable applications of 3D bioprinting in reproductive medicine. This systematic review aims to improve understanding, and focuses on applications in several branches of reproductive medicine. Advancements span the restoration of ovarian function, endometrial regeneration, vaginal reconstruction, and male germ cell bioengineering. 3D bioprinting holds untapped potential in reproductive medicine., (Copyright © 2024 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.)

Aim: In frozen-thawed embryo transfer (FET), differences in endometrial preparation methods affect the incidence of perinatal complications. However, the underlying causes are unclear. We aimed to investigate whether serum E2, P4 levels are associated with perinatal complications., Methods: This is a retrospective cohort study, involving 306 successful FET pregnancies from 2017 to 2022. Participants were divided into Natural Cycle (NC) and Hormone Replacement Cycle (HRC) group. We compared serum hormone levels, maternal backgrounds, and perinatal outcomes and complications. Furthermore, within the HRC group, serum hormone levels were compared for perinatal complications previously reported to show differences in incidence rates depending on the method of endometrial preparation., Results: HRC exhibited significantly higher serum E2 levels during the implantation period, but lower P4 levels during ovulation, implantation, and pregnancy test period compared with NC. HRC also had significantly higher rates of postpartum hemorrhage (PPH) and placenta accreta spectrum (PAS). There was no association found between perinatal complications more likely to occur in HRC and serum E2, P4 levels., Conclusions: In HRC, there were more occurrences of PPH and PAS. Although serum E2, P4 levels during FET did not correlate with perinatal complications., (© 2024 Japan Society of Obstetrics and Gynecology.)

Prostaglandins have many roles in the equine reproductive tract, including but not limited to luteolysis, luteal support, ovulation, transport through the uterine tube, uterine contraction, embryonic mobility, inflammation, and fibrosis. Altered secretion of inflammatory proteins are likely to disrupt the balance of endometrial function and could impair fertility. Our overall goal was to measure the expression of several prostaglandin- and inflammation-related genes in mares with different degrees of endometrial histological changes. Our hypothesis was that mares with neutrophilic and lymphocytic plasmocytic inflammation, fibrosis, or different biopsy grades would have altered concentrations of prostaglandin E2 (PGE2) and F2α (PGF2α), as well as altered expression of inflammation- and prostaglandin-related genes, compared to mares with minimal to no histological changes on biopsy evaluation. Forty-five endometrial biopsies from estrous mares were assessed by a reproductive pathologist for the degree of neutrophilic inflammation, lymphocytic and plasmocytic inflammation, and fibrosis, and a biopsy grade was assigned based on the Kenney-Doig system. A low-volume uterine lavage was collected from a subset of twenty-six mares prior to biopsy collection and was used to measure PGE2 and PGF2α concentrations via ELISA. Total RNA was extracted from biopsies and mRNA expression was evaluated for twenty-five genes of interest. A restricted maximum likelihood linear model was used to compare differences of mRNA expression, with a statistical significance set at P < 0.05. There was no difference in the abundance of PGE2 or PGF2α between any of the variables tested. Mares with endometrial biopsy grade I had lower expression of NF-kB, PTGS1 and HPGD compared to grade IIA or IIB (P < 0.05). Mares with neutrophilic inflammation had decreased expression of NF-kB, PTGS1, PTGER4, CBR1, mPGES2 and PTGIS compared to mares without inflammation. Mares with mild or minimal endometrial fibrosis had increased expression of mPGES2 and PTGIS, compared to mares with moderate endometrial fibrosis. In conclusion, several genes were identified to be differentially expressed in mares with histological changes compared to mares with no to minimal histological changes. The presence of inflammation and fibrosis may alter the concentration of prostaglandins in endometrial tissue, which could impair many of the uterine reproductive and immune functions during estrus, affecting early embryo survival., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The cytokine context present in the reproductive tract of cows is closely involved in normal uterine functions, including the estrous cycle and the establishment and maintenance of pregnancy. However, the roles of some cytokines in the uterus, and their relation with reproductive performance remain to be elucidated. Thus, this study aimed to examine the protein expression of several cytokines such as TNFα, IL-6, IL-8, IFNγ, IL-4, and TGF-β 3 in endometrial biopsies previous to conception, to evaluate the possible association with delayed conception in dairy cows. Protein expression levels were evaluated by immunohistochemistry. Results showed that the protein expression levels of TNFα, IL-6, IL-4 and TGF-β 3 were not associated with the parturition-conception interval, whereas the high protein expression levels of IFNγ were associated with the parturition-conception interval. Finally, the low protein expression of IL-8 showed a statistical tendency to be associated with delayed conception. This is the first report about the protein expression of IFN-γ in the endometrium of dairy cows and also, this cytokine could enhance the favorable conditions to achieve an early pregnancy., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

The complement system, composed of complement components and complement control proteins, plays an essential role in innate immunity. Complement system molecules are expressed at the maternal-conceptus interface, and inappropriate activation of the complement system is associated with various adverse pregnancy outcomes in humans and rodents. However, the expression, regulation, and function of the complement system at the maternal-conceptus interface in pigs have not been studied. In this study, we investigated the expression, localization, and regulation of complement system molecules at the maternal-conceptus interface in pigs. Complement components and complement control proteins were expressed in the endometrium, early-stage conceptus, and chorioallantoic tissues during pregnancy. The expression of complement components acting on the early stage of complement activation increased in the endometrium on Day 15 of pregnancy, with greater levels on that day compared with the estrous cycle. Localization of several complement components and complement control proteins was cell-type specific in the endometrium. The expression of C1QC, C2, C3, C4A, CFI, ITGB2, MASP1, and SERPING1 was increased by IFNG in endometrial explant tissues. Furthermore, cleaved C3 fragments were detected in endometrial tissues and uterine flushings on Day 15 of the estrous cycle and Day 15 of pregnancy, with greater levels on Day 15 of pregnancy. These results suggest that complement system molecules in pigs expressed at the maternal-conceptus interface play important roles in the establishment and maintenance of pregnancy by regulating innate immunity and modulating the maternal immune environment during pregnancy., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: The establishment and maintenance of pregnancy depend on endometrial competence. Asherman syndrome (AS) and intrauterine adhesions (IUA), or endometrial atrophy (EA) and thin endometrium (TE), can either originate autonomously or arise as a result from conditions (i.e. endometritis or congenital hypoplasia), or medical interventions (e.g. surgeries, hormonal therapies, uterine curettage or radiotherapy). Affected patients may present an altered or inadequate endometrial lining that hinders embryo implantation and increases the risk of poor pregnancy outcomes and miscarriage. In humans, AS/IUA and EA/TE are mainly treated with surgeries or pharmacotherapy, however the reported efficacy of these therapeutic approaches remains unclear. Thus, novel regenerative techniques utilizing stem cells, growth factors, or tissue engineering have emerged to improve reproductive outcomes., Objective and Rationale: This review comprehensively summarizes the methodologies and outcomes of emerging biotechnologies (cellular, acellular, and bioengineering approaches) to treat human endometrial pathologies. Regenerative therapies derived from human tissues or blood which were studied in preclinical models (in vitro and in vivo) and clinical trials are discussed., Search Methods: A systematic search of full-text articles available in PubMed and Embase was conducted to identify original peer-reviewed studies published in English between January 2000 and September 2023. The search terms included: human, uterus, endometrium, Asherman syndrome, intrauterine adhesions, endometrial atrophy, thin endometrium, endometritis, congenital hypoplasia, curettage, radiotherapy, regenerative therapy, bioengineering, stem cells, vesicles, platelet-rich plasma, biomaterials, microfluidic, bioprinting, organoids, hydrogel, scaffold, sheet, miRNA, sildenafil, nitroglycerine, aspirin, growth hormone, progesterone, and estrogen. Preclinical and clinical studies on cellular, acellular, and bioengineering strategies to repair or regenerate the human endometrium were included. Additional studies were identified through manual searches., Outcomes: From a total of 4366 records identified, 164 studies (3.8%) were included for systematic review. Due to heterogeneity in the study design and measured outcome parameters in both preclinical and clinical studies, the findings were evaluated qualitatively and quantitatively without meta-analysis. Groups using stem cell-based treatments for endometrial pathologies commonly employed mesenchymal stem cells (MSCs) derived from the human bone marrow or umbilical cord. Alternatively, acellular therapies based on platelet-rich plasma (PRP) or extracellular vesicles are gaining popularity. These are accompanied by the emergence of bioengineering strategies based on extracellular matrix (ECM)-derived hydrogels or synthetic biosimilars that sustain local delivery of cells and growth factors, reporting promising results. Combined therapies that target multiple aspects of tissue repair and regeneration remain in preclinical testing but have shown translational value. This review highlights the myriad of therapeutic material sources, administration methods, and carriers that have been tested., Wider Implications: Therapies that promote endometrial proliferation, vascular development, and tissue repair may help restore endometrial function and, ultimately, fertility. Based on the existing evidence, cost, accessibility, and availability of the therapies, we propose the development of triple-hit regenerative strategies, potentially combining high-yield MSCs (e.g. from bone marrow or umbilical cord) with acellular treatments (PRP), possibly integrated in ECM hydrogels. Advances in biotechnologies together with insights from preclinical models will pave the way for developing personalized treatment regimens for patients with infertility-causing endometrial disorders such as AS/IUA, EA/TE, and endometritis., Registration Number: https://osf.io/th8yf/., (© The Author(s) 2024. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology.)

Aims: Decreased oestrogen receptor (ER) expression is a marker of poor prognosis in endometrial carcinomas (EC) of no specific molecular profile (NSMP), but the optimal cut-off to separate high-risk 'low ER' versus low-risk 'high ER' expression has not been defined. Here we characterised the distribution of ER staining in a cohort of ECs., Methods and Results: Biopsy specimens from 120 cases of NSMP EC were stained for ER and assigned an Allred score. In 66 additional cases ER staining of matched biopsy and hysterectomy were compared. Twelve of 120 tumours had an Allred score of 0-3, including three endometrioid carcinomas (EEA) (one G1, two G3), four clear cell carcinomas (CCC), two mesonephric-like adenocarcinoma (MLA) and one each of: gastric-type adenocarcinoma, carcinosarcoma and endometrial carcinoma NOS. Three had Allred scores of 4-5: two MLA and one high-grade carcinoma with yolk sac differentiation. Five had Allred scores of 6: four EEA (one G1, one G2, two G3) and one mixed clear cell and endometrioid carcinoma. The remaining 100 tumours with Allred scores ≥ 7 were all EEA (66 G1, 28 G2, five G3 and one grade unknown). Comparing the biopsy versus hysterectomy ER staining (n = 66), the results were within a single Allred score point, except two cases with strong diffuse expression in the biopsy (Allred 8) and moderate expression in the hysterectomy (Allred 5)., Conclusions: Most NSMP ECs (> 80%) show high ER expression (Allred score ≥ 7). All non-endometrioid carcinomas and a few endometrioid carcinomas had lower ER expression (Allred score ≤ 6) or were completely negative., (© 2024 The Author(s). Histopathology published by John Wiley & Sons Ltd.)

Embryo implantation is composed of three steps: blastocyst apposition, adhesion/attachment and invasion. Blastocyst invasion has been studied less extensively than the other two events. Historically, studies conducted using electron microscopy have shown the removal of epithelial cells in the vicinity of the attached blastocysts in rodents, although the underlying mechanisms have remained unclear. Here, we describe recent studies using mice with uterine-specific gene deletion that demonstrated important roles for nuclear proteins such as progesterone receptor, hypoxia inducible factor and retinoblastoma in the regulation of embryo invasion. In these mouse models, the detachment of the endometrial luminal epithelium, decidualization in the stroma, and the activation of trophoblasts have been found to be important in ensuring embryo invasion. This review summarizes the molecular signaling associated with these cellular events, mainly evidenced by mouse models., (© 2024 Federation of European Biochemical Societies.)

Thyroid autoimmunity (TAI) has been linked to fertility disorders and pregnancy complications, even in euthyroid women. However, the exact pathophysiological mechanism underlying this association is not fully understood. This study seeks to investigate the expression of thyroid antigens within the human female reproductive system, potentially identifying targets for thyroid antibodies. Human biopsies of endometrium and follicular granulosa cells were collected and thyroperoxidase (TPO) and thyroglobulin (TG) expression was evaluated in these tissues by immunohistochemistry. Results showed, for the first time, the expression of TG protein and confirmed the presence of thyroid TPO in human endometrium and granulosa cells. Results suggest that TPO antibodies (TPOAbs) and TG antibodies (TGAbs) could interact with TPO and TG expressed in the reproductive system in patients with positive thyroid antibodies, thereby disrupting the function of TPO and TG and generating an inflammatory response, leading to fertility disorders and pregnancy complications., Competing Interests: The Authors declared no conflict of interest, (African Journal of Reproductive Health © 2024.)

Background Abnormal uterine bleeding (AUB) is one of the most common problems encountered in gynaecological practice. Defective endometrial angiogenesis has been implicated in various benign and malignant disorders of the endometrium. Aim This study aims to assess morphometry of endometrial glands and blood vessels in patients with AUB. Material and methods This is a one year retrospective cross sectional analysis of endometrial samples received with the diagnosis of AUB in reproductive age group. All samples were routinely processed and stained. Sections were analysed for morphometry of blood vessels and endometrial glands. Results A total of 374 cases were included. Most common histological group was proliferative followed by secretory phase. A significant difference was noted in mean vascular density, diameter, mitotic scores and height of glandular epithelium in different benign and malignant groups. Conclusion This study highlights the fact that glandular and vascular morphometry can be used to differentiate between various proliferative disorders of the endometrium. In the current era of new anti-angiogenic therapies, endometrial angiogenesis and changes in vascular morphology can be targeted, thus improving treatment modalities and patient care., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Institutional Ethics Committee, Guntur Medical College and Government General Hospital, Guntur issued approval GMC/IEC/20/2023, Dated 21-11-2023. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Itha et al.)

Introduction: Anandamide (AEA) and 2-arachidonoylglycerol are endogenous agonists of the cannabinoid receptors and regulate and control many cellular functions. Their activities are governed by enzymes and proteins that regulate their synthesis, receptor binding, transport, and degradation, which are known as the endocannabinoid system (ECS). The aim of this study was to investigate the regulation of endocannabinoid activity in the endometrium by studying the RNA and protein expression of the ECS within endometrial cell types and during different menstrual cycle stages and the impact of endometriosis. Materials and Methods: The RNA expression of 70 ECS genes was assessed using RNA sequencing of isolated endometrial epithelial and stromal cells. Subsequent immunofluorescence-stained endometrial samples on ECS components of interest were objectively analyzed via an agnostic and automated image analysis pipeline to extract quantitative information. Differential gene and protein expression was investigated between the two cell types, menstrual cycle phases, and endometriosis cases and controls. Results: Sufficient RNA expression was detected for 45 genes, and 17 (38%) genes were significantly different between epithelial and stromal cells. FAAH RNA was significantly higher in epithelial cells compared with stromal cells. Protein expression analysis of the main synthesizing (NAPE-PLD) and catabolizing (FAAH and NAAA) enzymes of AEA revealed a significantly stronger epithelial expression compared to stromal cells. The RNA and protein expression of CB1 receptors was very low with no significant difference between epithelial and stromal cells. Eleven ECS genes were regulated across the menstrual cycle, and there was no gene with significant difference between endometriosis cases and controls in epithelial cells. Discussion: Differential expression of ECS genes supports a cell type-specific endocannabinoid activity in the endometrium. As endocannabinoids are short-lived signaling molecules, higher RNA and protein expression of FAAH in the epithelial cells suggests an active regulation of endocannabinoid activity in epithelial cells within the endometrium.

Previous studies indicate a positive correlation between the duration of estrus prior to ovulation and likelihood of pregnancy in embryo recipient mares. However, the mechanisms by which the duration of estrus before may affect fertility remains unclear. This study aimed to determine the effect of different durations of estradiol exposure, prior to progesterone administration, on embryo viability in anestrous recipient mares, and endometrial expression of genes thought to influence embryo survival. Three groups of anestrous recipient mares treated with different duration of estradiol were used: long (LE), short (SE) and no treatment (NE). Day 8 embryos were transferred into recipient mares four days after long-acting progesterone administration and recovered 48h later to examine embryo growth and viability. The endometrial gene expression profile of selected genes was also investigated. The likelihood of recovering an embryo 48h after transfer was 46.1% (6/13), 62.5% (5/8) and 85.7% (6/7) for recipient mares from the NE, SE and LE groups, respectively (P = .09). Embryos recovered from the different groups of recipients did not, however, differ in size, morphology or the proportion of nuclei undergoing mitosis (P > .05). Abundance of mRNA for uterocalin (P19) and insulin-like growth factor 1 (IGF1) were increased in the LE compared to the NE group, while fibroblast growth factor 2 (FGF2), progesterone receptor (PGR) and insulin-like growth factor 1 receptor (IGF1R) transcript abundances were increased (P < 0.05) in the NE group compared to both SE and LE groups. In conclusion, a longer exposure of the endometrium to estradiol before progesterone tended to improve embryo survival within 48h of transfer. However, the grade, growth rate, and proportion of mitotic cells in surviving embryos did not differ among groups. If embryos are destined to fail in a suboptimal endometrial environment, they die and disappear quickly. Moreover, a more adequately estradiol-primed uterus, before the progesterone rise, seems to create a uterine environment, in terms of P19, IGF1, FGF2 and PGR gene expression, more conducive to embryo survival and further development., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Inflammation in the reproductive tract has become a serious threat to animal fertility. Recently, the role of peroxisome proliferator-activated receptor gamma (PPARγ) in the context of reproduction and the inflammatory response has been highlighted, but the role of PPARβ/δ has not been fully elucidated. The aim of the present study was to investigate the in vitro effect of PPARβ/δ ligands (agonist: L-165,041 and antagonist: GSK 3787) on the transcriptome profile of porcine endometrium during LPS-induced inflammation in the mid-luteal and follicular phases of the oestrous cycle (days 10-12 and 18-20, respectively) using the RNA-Seq method. During the mid-luteal phase of the oestrous cycle, the current study identified 145 and 143 differentially expressed genes (DEGs) after treatment with an agonist or antagonist, respectively. During the follicular phase of the oestrous cycle, 55 and 207 DEGs were detected after treatment with an agonist or antagonist, respectively. The detected DEGs are engaged in the regulation of various processes, such as the complement and coagulation cascade, NF-κB signalling pathway, or the pathway of 15-eicosatetraenoic acid derivatives synthesis. The results of the current study indicate that PPARβ/δ ligands are involved in the control of the endometrial inflammatory response., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)