Mechanisms of endometrial progesterone resistance

Transgenic mice applications in the study of endometriosis pathogenesis

Endometriosis (EM), characterized by ectopic growth of endometrial tissues and recurrent pelvic pain, is a common disease with severe negative impacts on the life quality of patients. Conventional uterine tissue transplantation-based models have been broadly used to investigate the pathogenic mechanism(s) of EM. Transgenic mice with whole body or uterine/pelvic tissue-specific labelling by the expression of GFP, β-gal or other light-emitting or chromogenic markers enable investigators to analyze the contribution to endometriotic lesions by the donor or recipient side after uterine tissue transplantation. Moreover, when coupled to uterine tissue transplantation, transgenic mice with a specific EM-related gene knocked out or overexpressed make it possible to determine the gene's in vivo role(s) for EM pathogenesis. Furthermore, observations on the rise of de novo endometriotic lesions as well as structural/functional changes in the eutopic endometrium or pelvic tissues after gene manipulation will directly relate the cognate gene to the onset of EM. A major advantage of transgenic EM models is their efficiency for analyzing gene interactions with hormonal, dietetic and/or environmental factors. This review summarizes the features/sources/backgrounds of transgenic mice and their applications to EM studies concerning hormonal regulation, angiogenesis and inflammation. Findings from these studies, the advantages/disadvantages of transgenic EM models, and future expectations are also discussed.

The role of HOTAIR in the modulation of resistance to anticancer therapy

Leading anti-tumour therapeutic strategies typically involve surgery and radiotherapy for locally advanced (non-metastatic) cancers, while hormone therapy, chemotherapy, and molecular targeted therapy are the current treatment options for metastatic cancer. Despite the initially high sensitivity rate to anticancer therapies, a large number of patients develop resistance, leading to a poor prognosis. The mechanisms related to drug resistance are highly complex, and long non-coding RNAs appear to play a crucial role in these processes. Among these, the lncRNA homeobox transcript antisense intergenic RNA (HOTAIR), widely implicated in cancer initiation and progression, likewise plays a significant role in anticancer drug resistance. It can modulate cell activities such as proliferation, apoptosis, hypoxia, autophagy, as well as epithelial-mesenchymal transition, thereby contributing to the development of resistant tumour cells. In this manuscript, we describe different mechanisms of antitumor drug resistance in which HOTAIR is involved and suggest its potential as a therapeutic predictive biomarker for the management of cancer patients.

The Known, the Unknown and the Future of the Pathophysiology of Endometriosis

Endometriosis is one of the most common causes of chronic pelvic pain and infertility, affecting 10% of women of reproductive age. A delay of up to 9 years is estimated between the onset of symptoms and the diagnosis of endometriosis. Endometriosis is currently defined as the presence of endometrial epithelial and stromal cells at ectopic sites; however, advances in research on endometriosis have some authors believing that endometriosis should be re-defined as "a fibrotic condition in which endometrial stroma and epithelium can be identified". There are several theories on the etiology of the disease, but the origin of endometriosis remains unclear. This review addresses the role of microRNAs (miRNAs), which are naturally occurring post-transcriptional regulatory molecules, in endometriotic lesion development, the inflammatory environment within the peritoneal cavity, including the role that cytokines play during the development of the disease, and how animal models have helped in our understanding of the pathology of this enigmatic disease.

Dienogest attenuates STAT3 activation in ovarian endometriotic cysts

OBJECTIVE

Recent studies have suggested that endometriosis could be the result of excessive activation of signal transducer and activator of transcription 3 (STAT3), which is associated with the regulation of essential cellular mechanisms such as proliferation, invasion, and apoptosis. That finding implies that regulating STAT3 activation could play a key role in treating endometriosis. In the present study, we aimed to evaluate whether the anti-endometriotic effects of dienogest is mediated by the regulation of STAT3 activation.

STUDY DESIGN

STAT3 activation was evaluated in normal endometrial and ovarian endometriotic tissues obtained from patients with/without preoperative dienogest treatment. A subsequent in vitro analysis with endometriotic cyst stromal cells (ECSCs) was used to confirm the direct influence of dienogest in STAT3 activation.

RESULT

STAT3 activation is significantly higher in endometriotic tissues from non-treated patients than in normal endometrial tissues, and that difference is reversed by preoperative administration of dienogest. Similarly, the inhibitory effects of dienogest on STAT3 activation are demonstrated by in vitro results showing that dienogest treatment significantly inhibits IL-6-stimulated STAT3 activation in cultured ECSCs. That inhibition was accompanied by decreased expression of proliferative (PCNA), invasive (MMP-2), and anti-apoptotic (BCL-2) proteins. Furthermore, downregulating STAT3 activity with siRNA decreased PCNA, MMP-2, and BCL-2 expression in IL-6-treated ECSCs.

CONCLUSION

Dienogest inhibits STAT3 activation in ECSCs, which affects their proliferation, invasiveness, and apoptosis.

Epigenetic Dysregulation in Endometriosis: Implications for Pathophysiology and Therapeutics

Endometriosis is a prevalent gynecological condition associated with pelvic pain and infertility. Despite more than a century of research, the etiology of endometriosis still eludes scientific consensus. This lack of clarity has resulted in suboptimal prevention, diagnosis, and treatment options. Evidence of genetic contributors to endometriosis is interesting but limited; however, significant progress has been made in recent years in identifying an epigenetic role in the pathogenesis of endometriosis through clinical studies, in vitro cell culture experiments, and in vivo animal models. The predominant findings include endometriosis-related differential expression of DNA methyltransferases and demethylases, histone deacetylases, methyltransferases, and demethylases, and regulators of chromatin architecture. There is also an emerging role for miRNAs in controlling epigenetic regulators in the endometrium and endometriosis. Changes in these epigenetic regulators result in differential chromatin organization and DNA methylation, with consequences for gene expression independent of a genetic sequence. Epigenetically altered expression of genes related to steroid hormone production and signaling, immune regulation, and endometrial cell identity and function have all been identified and appear to play into the pathophysiological mechanisms of endometriosis and resulting infertility. This review summarizes and critically discusses early seminal findings, the ever-growing recent evidence of epigenetic contributions to the pathophysiology of endometriosis, and implications for proposed epigenetically targeted therapeutics.

Organoid co-culture model of the human endometrium in a fully synthetic extracellular matrix enables the study of epithelial-stromal crosstalk

BACKGROUND

The human endometrium undergoes recurring cycles of growth, differentiation, and breakdown in response to sex hormones. Dysregulation of epithelial-stromal communication during hormone-mediated signaling may be linked to myriad gynecological disorders for which treatments remain inadequate. Here, we describe a completely defined, synthetic extracellular matrix that enables co-culture of human endometrial epithelial and stromal cells in a manner that captures healthy and disease states across a simulated menstrual cycle.

METHODS

We parsed cycle-dependent endometrial integrin expression and matrix composition to define candidate cell-matrix interaction cues for inclusion in a polyethylene glycol (PEG)-based hydrogel crosslinked with matrix metalloproteinase-labile peptides. We semi-empirically screened a parameter space of biophysical and molecular features representative of the endometrium to define compositions suitable for hormone-driven expansion and differentiation of epithelial organoids, stromal cells, and co-cultures of the two cell types.

FINDINGS

Each cell type exhibited characteristic morphological and molecular responses to hormone changes when co-encapsulated in hydrogels tuned to a stiffness regime similar to the native tissue and functionalized with a collagen-derived adhesion peptide (GFOGER) and a fibronectin-derived peptide (PHSRN-K-RGD). Analysis of cell-cell crosstalk during interleukin 1B (IL1B)-induced inflammation revealed dysregulation of epithelial proliferation mediated by stromal cells.

CONCLUSIONS

Altogether, we demonstrate the development of a fully synthetic matrix to sustain the dynamic changes of the endometrial microenvironment and support its applications to understand menstrual health and endometriotic diseases.

FUNDING

This work was supported by The John and Karine Begg Foundation, the Manton Foundation, and NIH U01 (EB029132).

In Memory of Ivo Brosens: Reflections on the Pathophysiology of Neonatal Uterine Bleeding

BACKGROUND

The occurrence of vaginal bleeding in early neonatal life has been observed for centuries and was considered a consequence of the sudden drop in circulating hormones following birth. As such, neonatal uterine bleeding was dismissed as having no clinical significance. Interest in the phenomenon was renewed when a new theory suggested a link between neonatal uterine bleeding (NUB) and accelerated endometrial maturation. This theory was based on the observation of a higher incidence of NUB in babies born post-term or after pregnancies complicated by intrauterine growth restriction, preeclampsia, or blood group incompatibility.

OBJECTIVE

The objective of this study was to review of available evidence on the pathogenesis of NUB.

METHOD

Review of available literature using Medline search (August 2022, no limit on start date or language) to identify articles that may link NUB with features of the uterus and/or endometrium.

OUTCOME

The fetal endometrial responses differ from that of the adult. In the fetus, the endometrium features progestogenic response only in a minority of cases. The endometrium in most newborn girls does not exhibit secretory or decidual changes which indicate lack of progesterone response. Most newborn girls do not have visible bleeding. Animal studies linked exogenous progestogen exposure during the period of organogenesis to poor endometrial gland development, progesterone resistance, and to alterations of reproductive performance. Although the fetal endometrium may not exhibit a full proliferative response, it is clearly sensitive to circulating estrogens. Molecular mechanisms involved in NUB may include "ontogenetic progesterone resistance."

CONCLUSION AND OUTLOOK

Endometrial development and its response to withdrawal of hormones at birth varies and may be affected by intrauterine stressors and gestational age. Factors that affect endometrial development during fetal life and in preterm neonates can have implications on future reproductive performance.

Distinct subtypes of endometriosis identified based on stromal-immune microenvironment and gene expression: implications for hormone therapy

Background

Endometriosis (EMs) is a chronic inflammatory condition that is highly heterogeneous. Current clinical staging fails to accurately predict drug responses and prognosis. In this study, we aimed to reveal the heterogeneity of ectopic lesions and investigate the possible underlying mechanisms using transcriptomic data and clinical information.

Methods

The EMs microarray dataset GSE141549 was obtained from the Gene Expression Omnibus database. Unsupervised hierarchical clustering was performed to identify EMs subtypes, which was followed by the functional enrichment analysis and estimation of immune infiltrates. Subtype-associated gene signatures were identified and further validated in other independent datasets, including GSE25628, E-MTAB-694, and GSE23339. Additionally, tissue microarrays (TMAs) were generated from premenopausal patients with EMs to investigate the potential clinical implications of the two identified subtypes.

Results

The unsupervised clustering analysis revealed that ectopic EMs lesions can be classified into two distinct subtypes: stroma-enriched (S1) and immune-enriched (S2). The functional analysis revealed that S1 correlated with fibroblast activation and extracellular matrix remodeling in the ectopic milieu, whereas S2 was characterized by the upregulation of immune pathways and a higher positive correlation with the immunotherapy response. Moreover, we identified a subtype signature composed of FHL1 and SORBS1, and constructed a subtype diagnostic model. Based on the cohort data from the TMAs, we found that S2 was strongly associated with the failure of/intolerance to hormone therapy.

Conclusions

This study identified two distinct subtypes that are varyingly associated with hormone resistance, stroma-immunity, and molecular features, thereby highlighting the importance of this stromal-immune heterogeneity in identifying EMs subtypes and providing novel insights into future personalized hormone-free therapy in EMs.

CFP1 governs uterine epigenetic landscapes to intervene in progesterone responses for uterine physiology and suppression of endometriosis

Progesterone (P₄) is required for the preparation of the endometrium for a successful pregnancy. P₄ resistance is a leading cause of the pathogenesis of endometrial disorders like endometriosis, often leading to infertility; however, the underlying epigenetic cause remains unclear. Here we demonstrate that CFP1, a regulator of H3K4me3, is required for maintaining epigenetic landscapes of P₄-progesterone receptor (PGR) signaling networks in the mouse uterus. Cfp1^f/f;Pgr-Cre (Cfp1^d/d) mice showed impaired P₄ responses, leading to complete failure of embryo implantation. mRNA and chromatin immunoprecipitation sequencing analyses showed that CFP1 regulates uterine mRNA profiles not only in H3K4me3-dependent but also in H3K4me3-independent manners. CFP1 directly regulates important P₄ response genes, including Gata2, Sox17, and Ihh, which activate smoothened signaling pathway in the uterus. In a mouse model of endometriosis, Cfp1^d/d ectopic lesions showed P₄ resistance, which was rescued by a smoothened agonist. In human endometriosis, CFP1 was significantly downregulated, and expression levels between CFP1 and these P₄ targets are positively related regardless of PGR levels. In brief, our study provides that CFP1 intervenes in the P₄-epigenome-transcriptome networks for uterine receptivity for embryo implantation and the pathogenesis of endometriosis.

A unified model of the biology of peripartum depression

Peripartum depression (PPD) is a prevalent and debilitating disorder that adversely affects the development of mothers and infants. Recently, there has been a plea for increased mental health screening during the peripartum period; however, currently, there is no accurate screening tool to identify women at risk of PPD. In addition, some women do not respond to current treatment schemes and develop treatment-resistant depression. The current perspective aims to propose a unified understanding of the biological underpinnings of PPD (UmPPD) that considers the heterogeneity in the onset, symptoms cluster, and severity of PPD. Such a model could promote basic and applied research on PPD and suggest new treatment avenues. The central hub of the model is the kynurenine pathway (KP) and the KP-serotonin ratio. The forces and specific processes at play that cause an imbalance within the KP and between KP and serotonin are inflammation, stress, reproductive hormones (especially estradiol and progesterone), and oxytocin. UmPPD predicts that the most severe PPD would comprise prolonged inflammation, ongoing or multiple stressors, excessive estrogen, progesterone resistance, and avoidance of breastfeeding, skin-to-skin contact, and social proximity. These factors would be associated with a higher likelihood of developing PPD, early onset, and more significant symptom severity. In addition, subtypes of PPD would consist of different compositions and expressions of these components, with one central common factor. UmPPD could aid in directing future research and possibly detecting critical processes that could help discover, develop, and utilize novel treatments for PPD.

Basolateral secretions of human endometrial epithelial organoids impact stromal cell decidualization

Uterine glands and, by inference, their secretions impact uterine receptivity, blastocyst implantation, stromal cell decidualization, and placental development. Changes in gland function across the menstrual cycle are primarily governed by the steroid hormones estrogen (E2) and progesterone (P4) but can also be influenced by extrinsic factors from the stroma. Using a human endometrial epithelial organoid system, transcriptome and proteome analyses identified distinct responses of the organoids to steroid hormones and prostaglandin E2 (PGE2). Notably, P4 and PGE2 modulated the basolateral secretion of organoid proteins, particularly cystatin C (CST3), serpin family A member 3 (SERPINA3), and stanniocalcin 1 (STC1). CST3, but not SERPINA3 or STC1, attenuated the in vitro stromal decidualization response to steroid hormones and PGE2. These findings provide evidence that uterine gland-derived factors impact stromal cell decidualization, which has implications for pregnancy establishment and fertility in women.

Endometrial hyperplasia and progesterone resistance: a complex relationship

The endometrium is one of the most dynamic tissues that constantly undergoes changes during the menstrual cycle in women of the reproductive period. All these processes take place mainly under the influence of steroid hormones that are produced in the woman’s body. However, it is important to remember that throughout life the endometrial tissue undergoes changes under the influence of various factors that lead to imbalances in hormonal regulation. All these changes can lead to the development of endometrial hyperplasia, which has a high risk of both recurrence and malignization. Over the past few decades, the incidence of endometrial cancer has increased in many countries. This trend is thought to be related to the increasing prevalence of obesity, as well as to changing female reproductive patterns. Although there are currently no well-established screening programmers for endometrial cancer, endometrial hyperplasia is a recognized precursor, and its detection provides an opportunity for prevention. Studying the pathogenesis and risk factors will give a great advantage in the future to prevent possible complications. At this point, the activity and inhibition of the different hormone isoforms can lead to different hyperplastic processes. The management of patients depends on many factors: age, species, reproductive potential and other factors. Therefore, a comprehensive approach to treatment is always necessary. In recent years, interest in the study of endometrial hyperplasia has increased dramatically due to the increase in endometrial cancer. Therefore, the issue of early diagnosis and prevention is most urgent in modern gynecology and requires further study. This review reflects the current understanding of the disruption of progesterone signaling mechanisms in endometrial hyperplasia according to domestic and foreign literature.

Therapeutic effects of melatonin on endometriosis, targeting molecular pathways: Current knowledge and future perspective

Endometriosis, the very serious disease in women creates a huge financial burden worldwide, which is comparable to diabetes mellitus. In addition to the typical pelvic pain, endometriosis is related to low life quality and decreased work efficiency; clinical consequences include mood complaints, metabolic impairments, inflammation, immunologic problems, and elevated malignancy risks. Several risk factors are correlated with endometriosis including elevated oxidative and nitrosative stress, long-lasting inflammation, raised immune tolerance, as well as autoimmunity. Melatonin is a natural molecule present throughout both the plant and animal kingdoms. It has numerous functions as an antioxidant and anti-inflammatory agent. Due to the anti-proliferative, antioxidant, anti-inflammatory, and anti-invasive features of melatonin, it performances as a beneficial agent to limit endometriosis; this involves several pathways including antiestrogenic, antioxidant, anti-inflammatory, and anti-apoptosis effects, as well as reducing the growth of E2-induced endometriotic tissue. Moreover, melatonin can favor sleep quality and decrease the unwanted signs in the patients. However, most of the data on melatonin accured from experimental works and additional clinical trials are needed. This review summarizes what is currently known regarding the influence of melatonin on endometriosis. AVAILABILITY OF DATA AND MATERIAL: Not applicable.

Focus on the role of NLRP3 inflammasome in the pathology of endometriosis: a review on molecular mechanisms and possible medical applications

Endometriosis (EMS) is a gynecological disease that leads to pathological conditions, which are connected to the initiation of pro-inflammatory cytokine production. Inflammation plays a vital role in the pathogenesis of EMS. The activation and formation of cytoplasmic inflammasome complexes is considered an important step of inflammation and a key regulator of pyroptosis, a form of cell death. NLR family pyrin domain containing 3 (NLRP3) inflammasome complex modulates innate immune activity and inflammation. The NLRP3 inflammasome activates cysteine protease caspase-1, which produces active pro-inflammatory interleukins (ILs), including IL-1β and IL-18. The aim of this review article was to discuss the involvement of NLRP3 inflammasome assembly and its activation in the pathophysiology of EMS and target related pathways in designing appropriate therapeutic approaches. Dysregulation of sex hormone signaling pathways was associated with over-activation of the NLPR3 inflammasome. In this study, we demonstrated the involvement of NLRP3 inflammasome signaling pathways in the pathophysiology of EMS. The manuscript also discusses the beneficial effects of targeted therapy through synthetic inhibitors of NLRP3 signaling pathways to control EMS lesions.

Progestin Resistance and Corresponding Management of Abnormal Endometrial Hyperplasia and Endometrial Carcinoma

With a younger tendency in morbidity age, endometrial cancer (EC) incidence has grown year after year. Worse, even more commonly occurring is endometrial hyperplasia (EH), which is a precancerous endometrial proliferation. For young women with early EC and EH who want to preserve fertility, progestin therapy has been utilized as a routine fertility-preserving treatment approach. Nevertheless, progestin medication failure in some patients is mostly due to progestin resistance and side effects. In order to further analyze the potential mechanisms of progestin resistance in EH and EC, to provide theoretical support for effective therapeutic strategies, and to lay the groundwork for searching novel treatment approaches, this article reviews the current therapeutic effects of progestin in EH and EC, as well as the mechanisms and molecular biomarkers of progestin resistance, and systematically expounds on the potential therapeutic methods to overcome progestin resistance.

Endometriosis-associated infertility: From pathophysiology to tailored treatment

Despite the clinically recognized association between endometriosis and infertility, the mechanisms implicated in endometriosis-associated infertility are not fully understood. Endometriosis is a multifactorial and systemic disease that has pleiotropic direct and indirect effects on reproduction. A complex interaction between endometriosis subtype, pain, inflammation, altered pelvic anatomy, adhesions, disrupted ovarian reserve/function, and compromised endometrial receptivity as well as systemic effects of the disease define endometriosis-associated infertility. The population of infertile women with endometriosis is heterogeneous, and diverse patients' phenotypes can be observed in the clinical setting, thus making difficult to establish a precise diagnosis and a single mechanism of endometriosis related infertility. Moreover, clinical management of infertility associated with endometriosis can be challenging due to this heterogeneity. Innovative non-invasive diagnostic tools are on the horizon that may allow us to target the specific dysfunctional alteration in the reproduction process. Currently the treatment should be individualized according to the clinical situation and to the suspected level of impairment. Here we review the etiology of endometriosis related infertility as well as current treatment options, including the roles of surgery and assisted reproductive technologies.

Zearalenone affects the growth of endometriosis via estrogen signaling and inflammatory pathways

Endometriosis is a chronic, inflammatory, estrogen-dependent gynecological disease characterized by the growth of endometrial stromal cells and glands outside the uterine cavity in response to hormones, which commonly occurs in reproductive-age women. Zearalenone (ZEA) is a toxic metabolite produced by Fusarium, which acts as estrogen activity because of the similarity of its structure to estrogen. In this study, we used an endometriosis mouse model: 15 days after ovariectomy, endometrial fragments were sutured on the pelvic wall, and exogenous estrogen was supplied using an estrogen-releasing silicone tube embedded subcutaneously. Mice were treated with different doses of ZEA by gavage for 21 days. The results show that ZEA significantly inhibited the growth of ectopic endometrium in a dose-dependent manner. The proliferation of cells decreased while apoptosis increased in the ectopic tissues of ZEA-treated mice compared to the vehicle group. The expression of estrogen receptor-α and its downstream targets MUC1 and p-AKT decreased, indicating an impaired estrogen signaling activity by ZEA treatment. In addition, the decreased expression of pro-inflammatory cytokine Tnf-α, Il-1β, and Il-6, the lower number of macrophages and neutrophils cells, and the inhibited NF-κB signaling pathway suggest the inflammatory response in the ectopic endometrium was also suppressed by ZEA treatment. However, when the exogenous estrogen supply is removed, ZEA, in turn, plays an estrogen-like role that promotes cell proliferation in the ectopic endometrium. In summary, our data suggest ZEA acts as an antagonist in endometriotic tissue when estrogen is sufficient but turns to estrogenic activity in the absence of estrogen in the development of endometriosis. ZEA also inhibits ectopic tissue growth by inhibiting inflammatory response in the endometriosis model.

The Gut Microbiota: A Double Edge Sword in Endometriosis

Endometriosis that afflicts 1 in 10 women of reproductive age is characterized by growth of endometrial tissue in the extra-uterine sites and encompasses metabolic-, immunologic- and endocrine-disruption. Importantly, several comorbidities are associated with endometriosis, especially autoimmune disorders such as inflammatory bowel disease. Primarily thought of as a condition arising from retrograde menstruation, emerging evidence uncovered a functional link between the gut microbiota and endometriosis. Specifically, recent findings revealed altered gut microbiota profiles in endometriosis and in turn this altered microbiota appears to be causal in the disease progression, implying a bi-directional crosstalk. In this review, we discuss the complex etiology and pathogenesis of endometriosis emphasizing on this recently recognized role of gut microbiome. We review the gut microbiome structure and functions and its complex network of interactions with the host for maintenance of homeostasis that is crucial for disease prevention. We highlight the underlying mechanisms on how some bacteria promotes disease progression and others protects against endometriosis. Further, we highlight the areas that require future emphases in the gut microbiome-endometriosis nexus and the potential microbiome-based therapies for amelioration of endometriosis.

Advances in the Application of Radionuclide-Labeled HER2 Affibody for the Diagnosis and Treatment of Ovarian Cancer

Human epidermal growth factor receptor 2 (HER2) is a highly expressed tumor marker in epithelial ovarian cancer, and its overexpression is considered to be a potential factor of poor prognosis. Therefore, monitoring the expression of HER2 receptor in tumor tissue provides favorable conditions for accurate localization, diagnosis, targeted therapy, and prognosis evaluation of cancer foci. Affibody has the advantages of high affinity, small molecular weight, and stable biochemical properties. The molecular probes of radionuclide-labeled HER2 affibody have recently shown broad application prospects in the diagnosis and treatment of ovarian cancer; the aim is to introduce radionuclides into the cancer foci, display systemic lesions, and kill tumor cells through the radioactivity of the radionuclides. This process seamlessly integrates the diagnosis and treatment of ovarian cancer. Current research and development of new molecular probes of radionuclide-labeled HER2 affibody should focus on overcoming the deficiencies of non-specific uptake in the kidney, bone marrow, liver, and gastrointestinal tract, and on reducing the background of the image to improve image quality. By modifying the amino acid sequence; changing the hydrophilicity, surface charge, and lipid solubility of the affibody molecule; and using different radionuclides, chelating agents, and labeling conditions to optimize the labeling method of molecular probes, the specific uptake of molecular probes at tumor sites will be improved, while reducing radioactive retention in non-target organs and obtaining the best target/non-target value. These measures will enable the clinical use of radionuclide-labeled HER2 affibody molecular probes as soon as possible, providing a new clinical path for tumor-specific diagnosis, targeted therapy, and efficacy evaluation. The purpose of this review is to describe the application of radionuclide-labeled HER2 affibody in the imaging and treatment of ovarian cancer, including its potential clinical value and dilemmas.

Hyperandrogenism and Polycystic ovary syndrome: Effects in pregnancy and offspring development

Polycystic ovary syndrome (PCOS) is one of the major endocrine disorders affecting women of reproductive age. Its etiology remains unclear. It is suggested that environmental factors, and particularly the intrauterine environment, play key roles in PCOS development. Besides the role of androgens in PCOS pathogenesis, exposure to endocrine disruptors, as is Bisphenol A, could also contribute to its development. Although PCOS is considered one of the leading causes of ovarian infertility, many PCOS patients can get pregnant. Some of them by natural conception and others by assisted reproductive technique treatments. As hyperandrogenism (one of PCOS main features) affects ovarian and uterine functions, PCOS women, despite reaching pregnancy, could present high-risk pregnancies, including implantation failure, an increased risk of gestational diabetes, preeclampsia, and preterm birth. Moreover, hyperandrogenism may also be maintained in these women during pregnancy. Therefore, as an altered uterine milieu, including hormonal imbalance, could affect the developing organisms, monitoring these patients throughout pregnancy and their offspring development is highly relevant. The present review focuses on the impact of androgenism and PCOS on fertility issues and pregnancy-related outcomes and offspring development. The evidence suggests that the increased risk of pregnancy complications and adverse offspring outcomes of PCOS women would be due to the factors involved in the syndrome pathogenesis and the related co-morbidities. A better understanding of the involved mechanisms is still needed and could contribute to a better management of these women and their offspring. This article is categorized under: Reproductive System Diseases > Molecular and Cellular Physiology Reproductive System Diseases > Environmental Factors.

The Modulatory Effect of Adipose-Derived Stem Cells on Endometrial Polyp Fibroblasts

Endometrial polyps (EPs) are benign overgrowths of the endometrium, with the potential to cause severe complications, ranging from discomfort to inflammation and infertility. Dysfunction of endometrial fibroblasts may be a critical component leading to the development of polyps. While surgical intervention is the common remedy for severe cases, it comes with drawbacks, including infection, bleeding, and risk of damage to the cervix and adjacent tissues. Adipose-derived mesenchymal stromal cells (ASCs) are at the focus of modern medicine, as key modulators of tissue homeostasis, inflammation and tissue repair, rendering them prime candidate agents for tissue regeneration and cell-based therapies. In the current work, endometrial polyps were isolated from patients admitted to the OB/GYN department at the Galilee Medical Center and extracted fibroblasts (EPFs) were isolated and characterized. ASCs were isolated from healthy patients. The effect of EPF- and ASC-conditioned media (CM) on polyp-derived fibroblasts was evaluated, in both 2D and 3D assays, as well as on the expression of matrix-related gene expression. Herein, EPFs exposed to ASC-CM exhibited reduced migration, invasion, contraction of hydrogels, and extracellular matrix deposition, compared to those exposed to EPF-CM. Altogether, the current work suggests that ASCs may have a modulating effect on fibroblasts involved in forming endometrial polyps and may serve as the basis for conservative treatment strategies aimed at treating severe cases of EPs.

SWI/SNF Antagonism of PRC2 Mediates Estrogen-Induced Progesterone Receptor Expression

Endometrial cancer (EC) is characterized by high estrogen levels unopposed by progesterone. Treatment with progestins is standard for early EC, but the response to progestins is dependent on progesterone receptor (PGR) expression. Here, we show that the expression of PGR in endometrial epithelial cells is dependent on ARID1A, a DNA-binding subunit of the SWI/SNF chromatin-remodeling complex that is commonly mutated in EC. In endometrial epithelial cells with estrogen receptor overexpression, we find that ARID1A promotes estrogen signaling and regulates common gene expression programs. Normally, endometrial epithelial cells expressing estrogen receptors respond to estrogen by upregulating the PGR. However, when ARID1A expression is lost, upregulation of PGR expression is significantly reduced. This phenomenon can also occur following the loss of the SWI/SNF subunit BRG1, suggesting a role for ARID1A- and BRG1-containing complexes in PGR regulation. We find that PGR is regulated by a bivalent promoter, which harbors both H3K4me3 and H3K27me3 histone tail modifications. H3K27me3 is deposited by EZH2, and inhibition of EZH2 in the context of ARID1A loss results in restoration of estrogen-induced PGR expression. Our results suggest a role for ARID1A deficiency in the loss of PGR in late-stage EC and a therapeutic utility for EZH2 inhibitors in this disease.

Loss of MIG-6 results in endometrial progesterone resistance via ERBB2

Female subfertility is highly associated with endometriosis. Endometrial progesterone resistance is suggested as a crucial element in the development of endometrial diseases. We report that MIG-6 is downregulated in the endometrium of infertile women with endometriosis and in a non-human primate model of endometriosis. We find ERBB2 overexpression in the endometrium of uterine-specific Mig-6 knockout mice (Pgr^cre/+Mig-6^f/f; Mig-6^d/d). To investigate the effect of ERBB2 targeting on endometrial progesterone resistance, fertility, and endometriosis, we introduce Erbb2 ablation in Mig-6^d/d mice (Mig-6^d/dErbb2^d/d mice). The additional knockout of Erbb2 rescues all phenotypes seen in Mig-6^d/d mice. Transcriptomic analysis shows that genes differentially expressed in Mig-6^d/d mice revert to their normal expression in Mig-6^d/dErbb2^d/d mice. Together, our results demonstrate that ERBB2 overexpression in endometrium with MIG-6 deficiency causes endometrial progesterone resistance and a nonreceptive endometrium in endometriosis-related infertility, and ERBB2 targeting reverses these effects.

Female subfertility is highly associated with endometriosis. Here the authors show that progesterone-induced MIG-6 is reduced in endometrium of infertile women and non-human primates with endometriosis, and in a mouse model find that Erbb2 is the key mediator of Mig-6 loss induced endometriosis-related infertility.

Role of SIRT1 and Progesterone Resistance in Normal and Abnormal Endometrium

CONTEXT

Progesterone resistance, a known pathologic condition associated with a reduced cellular response to progesterone and heightened estrogen responses, appears to have a normal physiologic role in mammalian reproduction. The molecular mechanism responsible for progesterone resistance in normal and abnormal endometrium remains unclear.

OBJECTIVE

To examine the roles of sirtuin-1 (SIRT1) in normal endometrium as well as endometrium associated with infertility and endometriosis, as an epigenetic modulator associated with progesterone resistance.

METHODS

SIRT1 expression was examined by Western blot, quantitative real-time polymerase chain reaction, and immunohistochemistry in mouse uterus and human endometrium. Mice with uterine specific Sirt1 overexpression were developed to examine SIRT1's role in endometrial function and endometriosis development. EX-527, a SIRT1 inhibitor, and SRT1720, a SIRT1 agonist, were also used to evaluate SIRT1 effect on endometriosis.

RESULTS

In normal healthy women, endometrial SIRT1 is expressed only during menses. SIRT1 was dramatically overexpressed in the endometrium from women with endometriosis in both the epithelium and stroma. In mice, SIRT1 is expressed at the time of implantation between day 4.5 and 5.5 of pregnancy. Overexpression of SIRT1 in the mouse uterus leads to subfertility due to implantation failure, decidualization defects and progesterone resistance. SIRT1 overexpression in endometriotic lesions promotes worsening endometriosis development. EX-527 significantly reduced the number of endometriotic lesions in the mouse endometriosis model.

CONCLUSIONS

SIRT1 expression and progesterone resistance appears to play roles in normal endometrial functions. Aberrant SIRT1 expression contributes to progesterone resistance and may participate in the pathophysiology of endometriosis. SIRT1 is a novel and targetable protein for the diagnosis as well as treatment of endometriosis and the associated infertility seen in this disease.

Progesterone Actions and Resistance in Gynecological Disorders

Estrogen and progesterone and their signaling mechanisms are tightly regulated to maintain a normal menstrual cycle and to support a successful pregnancy. The imbalance of estrogen and progesterone disrupts their complex regulatory mechanisms, leading to estrogen dominance and progesterone resistance. Gynecological diseases are heavily associated with dysregulated steroid hormones and can induce chronic pelvic pain, dysmenorrhea, dyspareunia, heavy bleeding, and infertility, which substantially impact the quality of women's lives. Because the menstrual cycle repeatably occurs during reproductive ages with dynamic changes and remodeling of reproductive-related tissues, these alterations can accumulate and induce chronic and recurrent conditions. This review focuses on faulty progesterone signaling mechanisms and cellular responses to progesterone in endometriosis, adenomyosis, leiomyoma (uterine fibroids), polycystic ovary syndrome (PCOS), and endometrial hyperplasia. We also summarize the association with gene mutations and steroid hormone regulation in disease progression as well as current hormonal therapies and the clinical consequences of progesterone resistance.

Research Progress on the Mechanism Between Polycystic Ovary Syndrome and Abnormal Endometrium

As a highly dynamic tissue, the endometrium is periodically shed in response to the secretion of estrogen and progesterone. After menarche, the endometrium of healthy women proliferates and differentiates under the action of steroid hormones (e.g., 17β-estradiol and progesterone) that are secreted by the ovaries to provide appropriate conditions for embryo implantation. Polycystic ovary syndrome (PCOS), a prevalent endocrine and metabolic disorder in reproductive-aged women, is usually associated with multiple cysts within the ovaries and excess levels of androgen and is characterized by hirsutism, acne, menstrual irregularity, infertility, and increased risk of insulin resistance. Multiple factors, such as anovulation, endocrine-metabolic abnormalities, and inflammation, can disrupt the endometrium in PCOS patients and can lead to endometrial hyperplasia, pregnancy complications, or even cancer. Despite many recent studies, the relationship between PCOS and abnormal endometrial function is still not fully understood. In this review, we investigate the correlation of PCOS patient endometrium with anovulation, hyperandrogenemia, insulin resistance, progesterone resistance, and inflammatory cytokines, aiming to provide a theoretical basis for the treatment of disorders caused by endometrial dysfunction in PCOS patients.

Effects of dual inhibition of AKT and ERK1/2 pathways on endometrial pro-inflammatory, hormonal, and epigenetic microenvironment in endometriosis

Endometriosis is an estrogen-dependent and progesterone-resistant gynecological inflammatory disease of reproductive-age women. The prevalence of endometriosis is ~5-10% in reproductive-age women, increasing to 20-30% in women with subfertility. The current anti-estrogen therapies can be prescribed only for a short time because of the undesirable side effects on menstruation, pregnancy, bone health, and failure to prevent a recurrence. The causes of endometriosis-associated infertility are multifactorial and poorly understood. The objective of the present study was to determine the inhibitory effects of AKT and/or ERK1/2 pathways on the microenvironment of the endometrium in a xenograft mouse model of endometriosis of human origin. Results indicate that dual inhibition of AKT and ERK1/2 pathways, but not inhibition of either AKT or ERK1/2 pathway, suppresses the growth of the endometriotic lesions in vivo. Dual inhibition of AKT and ERK1/2 pathways suppresses the production of proinflammatory cytokines, decreases E₂ biosynthesis and signaling, and restores progesterone receptor-B signaling components in the epithelial and stromal cells of the endometrium in a cell-specific manner. These results together suggest that dual inhibition of AKT and ERK1/2 pathways suppresses the estrogen-dominant state and concomitantly increases the progesterone-responsive state of the endometrium. Therefore, dual inhibition of AKT and ERK1/2 pathways could emerge as long-term nonsteroidal therapy for endometriosis.

Peritoneal fluid progesterone and progesterone resistance in superficial endometriosis lesions

Peritoneal fluid in ovulatory women is an ovarian exudate with higher estrogen and progesterone concentrations than in plasma. In the follicular phase, progesterone concentrations are as high as plasma concentrations in the luteal phase. After ovulation, estrogen and progesterone concentrations in the peritoneal fluid are 5-10 times higher than in plasma, both in women with and without endometriosis. The histologically proliferative aspect without secretory changes of most superficial subtle lesions is not compatible with the progesterone concentrations in the peritoneal fluid. Therefore, we have to postulate a strong progesterone resistance in these lesions. The mechanism is unclear and might be a peritoneal fluid effect in women with predisposing defects in the endometrium, or isolated endometrial glands with progesterone resistance, or subtle lesions originating from the basal endometrium: the latter hypothesis is attractive since in basal endometrium progesterone does not induce secretory changes while progesterone withdrawal, not occurring in peritoneal fluid, is required to resume mitotic activity and proliferation. Hormone concentrations in the peritoneal fluid are an important factor in understanding the medical therapy of endometriosis. The effect of oestro-progestin therapy on superficial endometriosis lesions seems to be a consequence of the decreased estrogen concentrations rather than a direct progestin effect. In conclusion, the peritoneal fluid, being a secretion product of the ovarian follicule, deserves more attention in the pathophysiology and treatment of endometriosis.

Uterine Adenomyosis: From Disease Pathogenesis to a New Medical Approach Using GnRH Antagonists

Uterine adenomyosis is a common chronic disorder frequently encountered in reproductive-age women, causing heavy menstrual bleeding, intense pelvic pain, and infertility. Despite its high prevalence, its etiopathogenesis is not yet fully understood, so there are currently no specific drugs to treat the disease. A number of dysregulated mechanisms are believed to contribute to adenomyosis development and symptoms, including sex steroid signaling, endometrial proliferation and invasiveness, and aberrant immune response. Abnormal sex steroid signaling, particularly hyperestrogenism and subsequent progesterone resistance, are known to play a pivotal role in its pathogenesis, which is why various antiestrogenic agents have been used to manage adenomyosis-related symptoms. Among them, gonadotropin-releasing hormone (GnRH) antagonists are swiftly gaining ground, with recent studies reporting efficient lesion regression and symptom alleviation. The aim of the present review is to compile available information on the pathogenesis of adenomyosis, explore the etiology and mechanisms of hyperestrogenism, and discuss the potential of antiestrogenic therapies for treating the disease and improving patient quality of life.

Hypo-Expression of Tuberin Promotes Adenomyosis via the mTOR1-Autophagy Axis

Adenomyosis (AM) is a disease in which endometrial tissue invades the myometrium and has a 10–60% prevalence in reproductive-aged women. TSC2 regulates autophagy via mTOR1 signalling in colorectal cancer and endometrial carcinoma. Dysregulation of autophagy is implicated in adenomyosis pathogenesis. However, whether TSC2 participates in adenomyosis via autophagy remains obscure. Here, we found that the expression of TSC2 in adenomyosis was significantly decreased than that in normal endometrium during the secretory phase. Moreover, TSC2 and autophagy marker expression was significantly lower in ectopic lesions than in eutopic samples. TSC2 downregulation inhibited autophagy through mTOR1 signalling pathway activation in endometrial cells, leading to excessive proliferation, migration, and EMT; TSC2 overexpression induced the opposite effects. Rapamycin treatment suppressed cell proliferation, migration and EMT in the absence of TSC2. In parallel, an autophagy-specific inhibitor (SAR-405) restored migration and EMT under rapamycin treatment in TSC2-knockdown Ishikawa cells. Finally, SAR-405 treatment promoted EMT and migration of overexpressing cells. Collectively, our results suggest that TSC2 controls endometrial epithelial cell migration and EMT by regulating mTOR1-autophagy axis activation and that hypo-expression of TSC2 in the endometrium might promote adenomyosis.

CNR1 may reverse progesterone-resistance of endometrial cancer through the ERK pathway

Endocrine therapy is a promising treatment for endometrial cancer (EC) that preserves fertility, however, progesterone-resistance is currently the major challenges. The Cancer Genome Atlas (TCGA) database analysis showed that CNR1 was closely have a negative correlation with overall survival (OS) and relapse-free survival (RFS) in endometrial cancer. To explore the role of CNR1 in progesterone resistance and possible molecular regulation mechanism, we established stable progesterone-resistant cell lines (IshikawaPR) via progesterone tolerance of ordinary cancer cells (Ishikawa). The difference of CNR1 level in two cell lines was assessed by MTT, RT-PCR, Western blot, immunofluorescence. Then, lentiviruses constructed CNR1-knockdown with GV248 as the tool vector were used to transfect IshikwaPR cells, and the changes of biological behavior and progesterone sensitivity was verified respectively through plate cloning experiment, EdU assay, flow cytometry cycle analysis, transwell, Scratch test, etc. We founded after CNR1 was knocked down, the proliferative activity and ability to migrate of IshikawaPR cells decreased, progesterone-response sensitivity could be improved. Moreover, knockdown of CNR1 can also down-regulate ERK and NFκ B expression and activation. Furthermore, subcutaneous xenograft in nude mice was tested similarly in vivo. The above datas suggest that targeting CNR1 may reverse the progesterone resistance in endometrial cancer and may coordinate the role of ERK pathway activation.

Nuclear factor-kappa B signaling in endometriotic stromal cells is not inhibited by progesterone owing to an aberrant endoplasmic reticulum stress response: a possible role for an altered inflammatory process in endometriosis

Endoplasmic reticulum (ER) stress serves as a key modulator of the inflammatory response by controlling nuclear factor-kappaB (NF-κB) signaling. Previous studies from our laboratory have reported an abnormal induction of ER stress linked to progesterone resistance in human endometriotic cells. Therefore, an aberrant ER stress response to progesterone might contribute to the altered inflammatory response observed in endometriotic tissues. To evaluate this hypothesis, we investigated whether ER stress is involved in regulation of NF-κB in endometrial stromal cells and whether induction of aberrant ER stress in endometriotic stromal cells affects pro-inflammatory cytokine production. We found that tunicamycin-induced ER stress inhibited NF-κB activation and pro-inflammatory cytokine (IL-6 and COX2) production in TNF-α- or IL-1β-treated normal endometrial stromal cells (NECSs). Tunicamycin increased the expression of A20 and C/EBPβ, which are negative regulators of NF-κB, and this increase inhibited NF-κB activity in NESCs incubated with TNF-α or IL-1β. Similarly, progesterone increased A20 and C/EBPβ expression through upregulation of ER stress in NESCs, resulting in inhibition of NF-κB activity and IL-6 and COX2 production. However, progesterone had no significant effects on induction of ER stress, A20 or C/EBPβ expression, NF-κB activity or IL-6 or COX2 production in ovarian endometriotic cyst stromal cells (ECSCs). In contrast, upregulation of ER stress by tunicamycin significantly reduced IL-6 and COX2 production by inhibiting NF-κB activity in ECSCs. In conclusion, our results suggest that NF-κB activity in endometriotic stromal cells was not inhibited because of an aberrant ER stress response to progesterone, resulting in an increase in pro-inflammatory cytokine production.

Dienogest regulates apoptosis, proliferation, and invasiveness of endometriotic cyst stromal cells via endoplasmic reticulum stress induction

Dienogest, a specific progesterone receptor agonist, is used in the treatment of endometriosis. However, it is still unclear as to the mechanisms of therapeutic effects on endometriosis. Our recent study showed that endometriosis may be the result of aberrant endoplasmic reticulum (ER) stress induction due to progesterone resistance. This finding suggests that the regulation of ER stress induction may play a key role in treatment of endometriosis. Therefore, the anti-endometriotic effects of dienogest may be mediated by regulation of ER stress. To test this hypothesis, we elucidate whether dienogest affects endometriotic stromal cell apoptosis, proliferation and invasiveness by modulating ER stress-induced CCAAT/enhancer-binding protein homologous protein (CHOP) expression. Specifically, PRKR-like ER kinase (PERK)/eukaryotic initiation factor 2α (eIF2α)/activating transcription factor 4 (ATF4), inositol-requiring kinase 1 (IRE1)/TNF receptor-associated factor 2 (TRAF2)/apoptosis signal-regulating kinase 1 (ASK1)/c-Jun N-terminal kinase (JNK) signaling, and downstream CHOP were evaluated to determine the involved ER stress-mediated regulation mechanism of CHOP expression. Our results show that progesterone treatment did not have any significant effects on ER stress, apoptosis, proliferation, and invasion in estrogen-treated endometriotic cyst stromal cells (ECSCs). However, dienogest treatment upregulated the induction of ER stress. It also led to increased apoptosis, and decreased proliferation and invasiveness. These dienogest-induced changes in apoptosis, proliferation and invasiveness were reversed by the ER stress inhibitor salubrinal. Furthermore, dienogest-induced ER stress increased CHOP expression through activation of both PERK/elf2α/ATF4 and IRE1/TRAF2/ASK1/JNK signaling. This upregulation was blocked by transfection with PERK and IRE1 siRNA, which decreased apoptosis and increased the proliferation and invasiveness of dienogest-treated ECSCs. Taken together, our findings indicate that dienogest enhances ER stress induction in endometriotic stromal cells, which affects apoptosis, proliferation and invasiveness via CHOP upregulation.

Widespread myofascial dysfunction and sensitisation in women with endometriosis-associated chronic pelvic pain: A cross-sectional study

BACKGROUND

Chronic pelvic pain persists in some women with endometriosis even after lesion removal and optimized hormonal treatment.

OBJECTIVE

Characterize the presence and distribution of pain, myofascial dysfunction and sensitisation beyond the pelvis in women with endometriosis-associated chronic pelvic pain.

METHODS

Cross-sectional study of 30 women prior to participation in a clinical trial. Evaluation included pain-focused abdominopelvic gynaecologic examination with the identification of pelvic floor muscle spasm. Neuro-musculoskeletal examination assessed paraspinal allodynia and hyperalgesia bilaterally and myofascial trigger points in 13 paired muscles. Pressure-pain thresholds were measured over interspinous ligaments and trigger points. Women completed the body territories element of the Body Pain Index.

RESULTS

All women had a pelvic floor muscle spasm that they self-identified as a major focus of pain. Twenty of 30 women described their pelvic pain as focal. However, all demonstrated widespread myofascial dysfunction with low pressure-pain thresholds and trigger points in over two-thirds of 26 assessed regions. Widespread spinal segmental sensitisation was present in 17/30, thoracic in 21/30 and lumbosacral/pelvic in 18/30. Cervical sensitisation manifested as low pressure-pain thresholds with 23/30 also reporting recurrent, severe headaches and 21/30 experiencing orofacial pain. Those reporting diffuse pelvic pain were more likely to have widespread (p = .024) and lumbosacral/pelvic (p = .036) sensitisation and report over 10 painful body areas (p = .009).

CONCLUSIONS

Women with endometriosis-associated chronic pelvic pain often have myofascial dysfunction and sensitisation beyond the pelvic region that may be initiated or maintained by on-going pelvic floor spasm. These myofascial and nervous system manifestations warrant consideration when managing pain in this population. Clinicaltrials.gov identifier: NCT01553201.

SIGNIFICANCE

Women with endometriosis often have pelvic pain persisting after surgery despite hormonal therapies and these women have regional pelvic sensitisation and myofascial dysfunction. Pelvic floor muscle spasm is a major pain focus in this population. Sensitisation and myofascial dysfunction are widespread, beyond the pelvic region. On-going pelvic floor spasm may initiate or maintain sensitisation. Myofascial/sensitisation manifestations warrant consideration when managing pain in this population.

A Systematic Two-Sample Mendelian Randomization Analysis Identifies Shared Genetic Origin of Endometriosis and Associated Phenotypes

Endometriosis, one of the most common gynecological disorders, is a complex disease characterized by the growth of endometrial-like tissue in extra-uterine locations and is a cause of pelvic pain and infertility. Evidence from observational studies indicate that endometriosis usually appears together with several other phenotypes. These include a list of autoimmune diseases, most of them more prevalent in women, anthropometric traits associated with leanness in the adulthood, as well as female reproductive traits, including altered hormone levels and those associated with a prolonged exposure to menstruation. However, the biological mechanisms underlying their co-morbidity remains unknown. To explore whether those phenotypes and endometriosis share a common genetic origin, we performed a systematic Two-Sample Mendelian Randomization (2SMR) analysis using public GWAS data. Our results suggest potential common genetic roots between endometriosis and female anthropometric and reproductive traits. Particularly, our data suggests that reduced weight and BMI might be mediating the genetic susceptibility to suffer endometriosis. Furthermore, data on female reproductive traits strongly suggest that genetic variants that predispose to a more frequent exposure to menstruation, through earlier age at menarche and shorter menstrual cycles, might also increase the risk to suffer from endometriosis.

Polycystic Ovary Syndrome and the Forgotten Uterus

Polycystic ovary syndrome (PCOS) is a common disorder that affects various facets of fertility. Although the ovarian and metabolic aspects of the disease is well studied, its role in uterine dysfunction is not well understood. Our objective was to review the features of endometrial and uterine aberrations in women with PCOS. A systematic literature search was performed in PubMed, Medline, and the Cochrane Library databases for papers published in English up to March 2020. The following key words were used for the search: polycystic ovary syndrome, poly cystic ovarian disease, polycystic ovaries, PCOS, PCOD, PCO, PCOM, oligoovulation, anovulation, oligomenorrhea, amenorrhea, hyperandrogenism and this was combined with terms; endometrium, infertility, uterus, progesterone resistance, endometrial hyperplasia, pregnancy outcomes, preterm delivery. In this review, we highlight various uterine pathologies that are associated with PCOS and explore its impact on fertility. We also discuss key uterine molecular pathways that are altered in PCOS that may be related to infertility, endometrial hyperplasia and cancer.

Endometrial function in women with polycystic ovary syndrome: a comprehensive review

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility. An endometrial component has been suggested to contribute to subfertility and poor reproductive outcomes in affected women.

OBJECTIVE AND RATIONALE

The aim of this review was to determine whether there is sufficient evidence to support that endometrial function is altered in women with PCOS, whether clinical features of PCOS affect the endometrium, and whether there are evidence-based interventions to improve endometrial dysfunction in PCOS women.

SEARCH METHODS

An extensive literature search was performed from 1970 up to July 2020 using PubMed and Web of Science without language restriction. The search included all titles and abstracts assessing a relationship between PCOS and endometrial function, the role played by clinical and biochemical/hormonal factors related to PCOS and endometrial function, and the potential interventions aimed to improve endometrial function in women with PCOS. All published papers were included if considered relevant. Studies having a specific topic/hypothesis regarding endometrial cancer/hyperplasia in women with PCOS were excluded from the analysis.

OUTCOMES

Experimental and clinical data suggest that the endometrium differs in women with PCOS when compared to healthy controls. Clinical characteristics related to the syndrome, alone and/or in combination, may contribute to dysregulation of endometrial expression of sex hormone receptors and co-receptors, increase endometrial insulin-resistance with impaired glucose transport and utilization, and result in chronic low-grade inflammation, immune dysfunction, altered uterine vascularity, abnormal endometrial gene expression and cellular abnormalities in women with PCOS. Among several interventions to improve endometrial function in women with PCOS, to date, only lifestyle modification, metformin and bariatric surgery have the highest scientific evidence for clinical benefit.

WIDER IMPLICATIONS

Endometrial dysfunction and abnormal trophoblast invasion and placentation in PCOS women can predispose to miscarriage and pregnancy complications. Thus, patients and their health care providers should advise about these risks. Although currently no intervention can be universally recommended to reverse endometrial dysfunction in PCOS women, lifestyle modifications and metformin may improve underlying endometrial dysfunction and pregnancy outcomes in obese and/or insulin resistant patients. Bariatric surgery has shown its efficacy in severely obese PCOS patients, but a careful evaluation of the benefit/risk ratio is warranted. Large scale randomized controlled clinical trials should address these possibilities.

Physiomimetic Models of Adenomyosis

Adenomyosis remains an enigmatic disease in the clinical and research communities. The high prevalence, diversity of morphological and symptomatic presentations, array of potential etiological explanations, and variable response to existing interventions suggest that different subgroups of patients with distinguishable mechanistic drivers of disease may exist. These factors, combined with the weak links to genetic predisposition, make the entire spectrum of the human condition challenging to model in animals. Here, after an overview of current approaches, a vision for applying physiomimetic modeling to adenomyosis is presented. Physiomimetics combines a system's biology analysis of patient populations to generate hypotheses about mechanistic bases for stratification with in vitro patient avatars to test these hypotheses. A substantial foundation for three-dimensional (3D) tissue engineering of adenomyosis lesions exists in several disparate areas: epithelial organoid technology; synthetic biomaterials matrices for epithelial–stromal coculture; smooth muscle 3D tissue engineering; and microvascular tissue engineering. These approaches can potentially be combined with microfluidic platform technologies to model the lesion microenvironment and can potentially be coupled to other microorgan systems to examine systemic effects. In vitro patient-derived models are constructed to answer specific questions leading to target identification and validation in a manner that informs preclinical research and ultimately clinical trial design.

Offspring sex and risk of epithelial ovarian cancer: a multinational pooled analysis of 12 case-control studies

While childbearing protects against risk of epithelial ovarian cancer (EOC), few studies have explored the impact on maternal EOC risk of sex of offspring, which may affect the maternal environment during pregnancy. We performed a pooled analysis among parous participants from 12 case-controls studies comprising 6872 EOC patients and 9101 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariable logistic regression for case-control associations and polytomous logistic regression for histotype-specific associations, all adjusted for potential confounders. In general, no associations were found between offspring sex and EOC risk. However, compared to bearing only female offspring, bearing one or more male offspring was associated with increased risk of mucinous EOC (OR = 1.45; 95% CI = 1.01-2.07), which appeared to be limited to women reporting menarche before age 13 compared to later menarche (OR = 1.71 vs 0.99; P-interaction = 0.02). Bearing increasing numbers of male offspring was associated with greater risks of mucinous tumors (OR = 1.31, 1.84, 2.31, for 1, 2 and 3 or more male offspring, respectively; trend-p = 0.005). Stratifying by hormonally-associated conditions suggested that compared to bearing all female offspring, bearing a male offspring was associated with lower risk of endometrioid cancer among women with a history of adult acne, hirsutism, or polycystic ovary syndrome (OR = 0.49, 95% CI = 0.28-0.83) but with higher risk among women without any of those conditions (OR = 1.64 95% CI = 1.14-2.34; P-interaction = 0.003). Offspring sex influences the childbearing-EOC risk relationship for specific histotypes and conditions. These findings support the differing etiologic origins of EOC histotypes and highlight the importance of EOC histotype-specific epidemiologic studies. These findings also suggest the need to better understand how pregnancy affects EOC risk.

In vitro models of the human endometrium: evolution and application for women's health

The endometrium is the inner lining of the uterus that undergoes complex regeneration and differentiation during the human menstrual cycle. The process of endometrial shedding, regeneration, and differentiation is driven by ovarian steroid hormones and prepares the endometrium and intrauterine environment for embryo implantation and pregnancy establishment. Endometrial glands and their secretions are essential for pregnancy establishment, and cross talk between the glandular epithelium and stromal cells appears vital for decidualization and placental development. Despite being crucial, the biology of the human endometrium during pregnancy establishment and most of pregnancy is incomplete, given the ethical and practical limitations of obtaining and studying endometrium from pregnant women. As such, in vitro models of the human endometrium are required to fill significant gaps in understanding endometrial biology. This review is focused on the evolution and development of in vitro three-dimensional models of the human endometrium and provides insight into the challenges and promises of those models to improve women's reproductive health.

Progesterone promotes embryo adhesion by upregulating c-Fos/c-Jun transcription factor-mediated poFUT1 expression†

The proliferation and adhesion abilities of placental trophoblasts are critical for embryo implantation and successful pregnancy. Protein O-fucosyltransferase 1 (poFUT1) and the transcription factor c-Fos/c-Jun have been found to promote trophoblastic cell invade into the endometrium. Progesterone is critical to the regulation of embryonic implantation. However, the exact role of poFUT1 in embryo proliferation and adhesion to the endometrium, and the relationship between progesterone, c-Fos/c-Jun, and poFUT1 has not been studied in detail. In the current study, we found that the serum levels of poFUT1 and progesterone significantly was decreased in miscarriage patients compared with those in normal pregnancy women, and there is a positive correlation between the changes in progesterone and poFUT1. Employing a human embryo trophoblastic cell line (JAR), we showed that progesterone facilitated the activation of c-Fos/c-Jun. Using an electrophoretic mobility shift assay and chromatin immunoprecipitation, we confirmed that the specific transcription factor c-Fos/c-Jun regulated the poFUT1 promoter, which could enhance poFUT1 transcriptional activity, thus further increasing trophoblast cell proliferation and adhesion potential. Taking these findings together, progesterone upregulates poFUT1 expression via the specific transcription factor c-Fos/c-Jun, and then increase trophoblast cell proliferation and adhesion potential. poFUT1 and progesterone may be used together as potential markers of miscarriage, and they may be diagnostic and therapeutic targets for miscarriage.

90 YEARS OF PROGESTERONE: New insights into progesterone receptor signaling in the endometrium required for embryo implantation

Progesterone's ability to maintain pregnancy in eutherian mammals highlighted this steroid as the 'hormone of pregnancy'. It was the unique 'pro-gestational' bioactivity of progesterone that enabled eventual purification of this ovarian steroid to crystalline form by Willard Myron Allen in the early 1930s. While a functional connection between normal progesterone responses ('progestational proliferation') of the uterus with the maintenance of pregnancy was quickly appreciated, an understanding of progesterone's involvement in the early stages of pregnancy establishment was comparatively less well understood. With the aforementioned as historical backdrop, this review focuses on a selection of key advances in our understanding of the molecular mechanisms by which progesterone, through its nuclear receptor (the progesterone receptor), drives the development of endometrial receptivity, a transient uterine state that allows for embryo implantation and the establishment of pregnancy. Highlighted in this review are the significant contributions of advanced mouse engineering and genome-wide transcriptomic and cistromic analytics which reveal the pivotal molecular mediators and modifiers that are essential to progesterone-dependent endometrial receptivity and decidualization. With a clearer understanding of the molecular landscape that underpins uterine responsiveness to progesterone during the periimplantation period, we predict that common gynecologic morbidities due to abnormal progesterone responsiveness will be more effectively diagnosed and/or treated in the future.

Steroid hormones regulate genome-wide epigenetic programming and gene transcription in human endometrial cells with marked aberrancies in endometriosis

Programmed cellular responses to cycling ovarian-derived steroid hormones are central to normal endometrial function. Abnormalities therein, as in the estrogen-dependent, progesterone-"resistant" disorder, endometriosis, predispose to infertility and poor pregnancy outcomes. The endometrial stromal fibroblast (eSF) is a master regulator of pregnancy success. However, the complex hormone-epigenome-transcriptome interplay in eSF by each individual steroid hormone, estradiol (E2) and/or progesterone (P4), under physiologic and pathophysiologic conditions, is poorly understood and was investigated herein. Genome-wide analysis in normal, early and late stage eutopic eSF revealed: i) In contrast to P4, E2 extensively affected the eSF DNA methylome and transcriptome. Importantly, E2 resulted in a more open versus closed chromatin, confirmed by histone modification analysis. Combined E2 with P4 affected a totally different landscape than E2 or P4 alone. ii) P4 responses were aberrant in early and late stage endometriosis, and mapping differentially methylated CpG sites with progesterone receptor targets from the literature revealed different but not decreased P4-targets, leading to question the P4-"resistant" phenotype in endometriosis. Interestingly, an aberrant E2-response was noted in eSF from endometriosis women; iii) Steroid hormones affected specific genomic contexts and locations, significantly enriching enhancers and intergenic regions and minimally involving proximal promoters and CpG islands, regardless of hormone type and eSF disease state. iv) In eSF from women with endometriosis, aberrant hormone-induced methylation signatures were mainly due to existing DNA methylation marks prior to hormone treatments and involved known endometriosis genes and pathways. v) Distinct DNA methylation and transcriptomic signatures revealed early and late stage endometriosis comprise unique disease subtypes. Taken together, the data herein, for the first time, provide significant insight into the hormone-epigenome-transcriptome interplay of each steroid hormone in normal eSF, and aberrant E2 response, distinct disease subtypes, and pre-existing epigenetic aberrancies in the setting of endometriosis, provide mechanistic insights into how endometriosis affects endometrial function/dysfunction.

Progesterone's role in deep infiltrating endometriosis: Progesterone receptor and estrogen metabolism enzymes expression and physiological changes in primary endometrial stromal cell culture

To study progesterone signaling activation, we measured changes in extracellular pH as a reflection of Na+/H+ exchange (NHE) using a cytosensor microphysiometer and assessed progesterone receptor (PR) and estrogen metabolism enzymes mRNA expression in cultured endometrial cells from women with deep infiltrating endometriosis and healthy controls using real-time quantitative PCR. This study was conducted at a University hospital and included patients with and without deep infiltrating endometriosis (DIE). Primary endometrial stromal cells (ECs) from women with DIE and controls were treated with 17β-estradiol and progesterone prior to microphysiometer measurements and qPCR evaluations. Decreased progesterone responsiveness and decreased total nuclear PR and HSD17B1 mRNA expression were observed in cultured ECs from women with deep infiltrating endometriosis relative to those from control samples before and after hormone treatment. These cells also showed increased 17β-hydroxysteroid dehydrogenases types 2 (HSD17B2) relative to control group and increased expression of aromatase (CYP19) after exposure to progesterone. These physiological and expression patterns observed in ECs cultures from women with DIE reinforces previous findings in the literature supporting the progesterone resistance hypothesis in the pathogenesis of endometriosis.

Challenges in uncovering non-invasive biomarkers of endometriosis

Endometriosis affects up to 10% of women of childbearing age, causing symptoms that can include chronic pelvic pain and reduced fertility. The symptoms are not specific to the disease and can be confused with other gynecological conditions or normal menstruation. Currently, the disease can be only definitively diagnosed by laparoscopy, as no clinically accepted biomarker exists. Biomarker discovery can either follow a hypothesis-driven approach selecting targets to be tested based on current knowledge of the disease, or take an unbiased high-throughput screening “omics” approach, such as transcriptomics or proteomics, to identify markers that are unique or elevated in accessible bodily fluids of patients with the disease. Numerous studies have been conducted using these approaches to try and identify endometriosis biomarkers, but variabilities in study design, cohort selection, and analysis, together with the fact that most studies were small-scale, have made independent validation of biomarker candidates difficult. Therefore, efforts are underway to standardize cohort selection, patient data, and sample collection to allow better cross-study comparisons. Large scale multi-center studies using this standardized approach are necessary to validate existing endometriosis biomarker candidates and uncover potential new markers. Given the complexity and heterogeneity of the disease, it is likely that a panel of biomarkers will be necessary to diagnose and categorize endometriosis.

Endometriosis and Pregnancy: A Single Institution Experience

Endometriosis may compromise the physiological course of pregnancy. The aim of this prospective observational study was to evaluate whether endometriosis causes a higher prevalence of obstetric and neonatal complications as well as a higher risk of caesarean section and to detect a possible correlation between the presence, type, and location of endometriosis and obstetric complications, previous surgery, and pregnancy outcome, as well as the influence of pregnancy on the course of the disease. We compared two cohorts of women with spontaneous pregnancy, with and without endometriosis. Obstetric and neonatal outcomes, mode of delivery, presence, type, and location of endometriotic lesions and the effect of pregnancy on the disease were analyzed. A total of 425 pregnancies were evaluated: 145 cases and 280 controls. Patients with endometriosis showed a higher incidence of miscarriage, threatened miscarriage, threatened preterm labor, preterm delivery, placental abruption, and a higher incidence of caesarean section. A significant correlation with pregnancy-induced hypertension and preeclampsia was found in the presence of adenomyosis. No difference in fetal outcome was found. One case of hemoperitoneum during pregnancy was observed. Pregnancy in women with endometriosis carries a higher risk of obstetric complications, such as miscarriage, threatened miscarriage, preterm labor, preterm birth, and a higher caesarean section rate. Endometriosis does not seem to influence fetal well-being.