A new isoform of steroid receptor coactivator-1 is crucial for pathogenic progression of endometriosis

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 pathogenesis of endometriosis and adenomyosis: insights from single-cell RNA sequencing†

Endometriosis and adenomyosis are two similar gynecological diseases that are characterized by ectopic implantation and the growth of the endometrial tissue. Previous studies have reported that they share a common pathophysiology in some respects, such as a similar cellular composition and resistance to the progestogen of lesions, but their underlying mechanisms remain elusive. Emerging single-cell ribonucleic acid sequencing (scRNA-seq) technologies allow for the dissection of single-cell transcriptome mapping to reveal the etiology of diseases at the level of the individual cell. In this review, we summarized the published findings in research on scRNA-seq regarding the cellular components and molecular profiles of diverse lesions. They show that epithelial cell clusters may be the vital progenitors of endometriosis and adenomyosis. Subclusters of stromal cells, such as endometrial mesenchymal stem cells and fibroblasts, are also involved in the occurrence of endometriosis and adenomyosis, respectively. Moreover, CD8+ T cells, natural killer cells, and macrophages exhibit a deficiency in clearing the ectopic endometrial cells in the immune microenvironment of endometriosis. It seems that the immune responses are activated in adenomyosis. Understanding the immune characteristics of adenomyosis still needs further exploration. Finally, we discuss the application of findings from scRNA-seq for clinical diagnosis and treatment. This review provides fresh insights into the pathogenesis of endometriosis and adenomyosis as well as the therapeutic targets at the cellular level.

Immune pathway through endometriosis to ovarian cancer

Endometriosis is an estrogen-dependent inflammatory disease, defined by the presence of functional endometrial tissue outside of the uterine cavity. This disease is one of the main gynecological diseases, affecting around 10%-15% women and girls of reproductive age, being a common gynecologic disorder. Although endometriosis is a benign disease, it shares several characteristics with invasive cancer. Studies support that it has been linked with an increased chance of developing endometrial ovarian cancer, representing an earlier stage of neoplastic processes. This is particularly true for women with clear cell carcinoma, low-grade serous carcinoma and endometrioid. However, the carcinogenic pathways between both pathologies remain poorly understood. Current studies suggest a connection between endometriosis and endometriosis-associated ovarian cancers (EAOCs) via pathways associated with oxidative stress, inflammation, and hyperestrogenism. This article aims to review current data on the molecular events linked to the development of EAOCs from endometriosis, specifically focusing on the complex relationship between the immune response to endometriosis and cancer, including the molecular mechanisms and their ramifications. Examining recent developments in immunotherapy and their potential to boost the effectiveness of future treatments.

Multi-Body Biomarker Entrapment System: An All-Encompassing Tool for Ultrasensitive Disease Diagnosis and Epidemic Screening

Ultrasensitive identification of biomarkers in biofluids is essential for the precise diagnosis of diseases. For the gold standard approaches, polymerase chain reaction and enzyme-linked immunosorbent assay, cumbersome operational steps hinder their point-of-care applications. Here, a bionic biomarker entrapment system (BioES) is implemented, which employs a multi-body Y-shaped tetrahedral DNA probe immobilized on carbon nanotube transistors. Clinical identification of endometriosis is successfully realized by detecting an estrogen receptor, ERβ, from the lesion tissue of endometriosis patients and establishing a standard diagnosis procedure. The multi-body Y-shaped BioES achieves a theoretical limit of detection (LoD) of 6.74 aM and a limit of quantification of 141 aM in a complex protein milieu. Furthermore, the BioES is optimized into a multi-site recognition module for enhanced binding efficiency, realizing the first identification of monkeypox virus antigen A35R and unamplified detection of circulating tumor DNA of breast cancer in serum. The rigid and compact probe framework with synergy effect enables the BioES to target A35R and DNA with a LoD down to 991 and 0.21 aM, respectively. Owing to its versatility for proteins and nucleic acids as well as ease of manipulation and ultra-sensitivity, the BioES can be leveraged as an all-encompassing tool for population-wide screening of epidemics and clinical disease diagnosis.

Potential Significance of Serum Autoantibodies to Endometrial Antigens, α-Enolase and Hormones in Non-Invasive Diagnosis and Pathogenesis of Endometriosis

The objective of the study was to evaluate the profile of serum autoantibodies and their diagnostic and pathogenetic significance in ovarian endometrioma (OEM) and deep infiltrative endometriosis (DIE). The study enrolled 74 patients with endometriosis (Group 1), including 53 patients with OEM (Subgroup 1a); 21 patients with DIE without ovarian lesions (Subgroup 1b); and 27 patients without endometriosis (Group 2). The diagnosis was confirmed by laparoscopic surgery and histologic examination of resected tissues. Antibodies (M, G) to tropomyosin 3 (TPM), tropomodulin 3 (TMOD), α-enolase (ENO), estradiol (E2), progesterone (PG), and human chorionic gonadotropin (hCG) were identified in blood serum using modified ELISA. In endometriosis, antibodies to endometrial antigens, hormones, and ENO were detected more often than antiphospholipid and antinuclear antibodies. Higher levels of IgM to TPM, hCG, E2, and PG and IgG to TMOD, ENO, E2, and hCG were found in Subgroup 1a compared to Group 2. IgM to TPM, hCG, E2, PG, and IgG to E2 and ENO had a high diagnostic value for OEM (AUC > 0.7), with antibodies to TPM having the highest sensitivity and specificity (73.6% and 81.5%). In Subgroup 1b, only the levels of IgM to TPM and hCG were higher than in Group 2. These antibodies had a high diagnostic value for DIE. Thus, endometriosis is associated with autoantibodies to endometrial antigens, α-enolase, steroid, and gonadotropic hormones. A wider spectrum of antibodies is detected in OEM than in DIE. These antibodies have a high diagnostic value for OEM and DIE and potential pathogenetic significance for endometriosis and associated infertility.

Ginsenosides in endometrium-related diseases: Emerging roles and mechanisms

Ginsenosides, agents extracted from an important herb (ginseng), are expected to provide new therapies for endometrium-related diseases. Based on the molecular types of ginsenosides, we reviewed the main pharmacological effects of ginsenosides against endometrium-related diseases (e.g., endometrial cancers, endometriosis, and endometritis). The mechanism of action of ginsenosides involves inducing apoptosis of endometrium-related cells, promoting autophagy of endometrium-related cells, regulating epithelial-mesenchymal transition (EMT) in endometrium-related cells, and activating the immune system to kill cells associated with endometrial diseases. We hope to provide a theoretical foundation for the treatment of endometrium-related diseases by ginsenosides.

Fusobacterium infection facilitates the development of endometriosis through the phenotypic transition of endometrial fibroblasts

Retrograde menstruation is a widely accepted cause of endometriosis. However, not all women who experience retrograde menstruation develop endometriosis, and the mechanisms underlying these observations are not yet understood. Here, we demonstrated a pathogenic role of Fusobacterium in the formation of ovarian endometriosis. In a cohort of women, 64% of patients with endometriosis but <10% of controls were found to have Fusobacterium infiltration in the endometrium. Immunohistochemical and biochemical analyses revealed that activated transforming growth factor-β (TGF-β) signaling resulting from Fusobacterium infection of endometrial cells led to the transition from quiescent fibroblasts to transgelin (TAGLN)-positive myofibroblasts, which gained the ability to proliferate, adhere, and migrate in vitro. Fusobacterium inoculation in a syngeneic mouse model of endometriosis resulted in a marked increase in TAGLN-positive myofibroblasts and increased number and weight of endometriotic lesions. Furthermore, antibiotic treatment largely prevented establishment of endometriosis and reduced the number and weight of established endometriotic lesions in the mouse model. Our data support a mechanism for the pathogenesis of endometriosis via Fusobacterium infection and suggest that eradication of this bacterium could be an approach to treat endometriosis.

Research advances in endometriosis-related signaling pathways: A review

Endometriosis (EM) is characterized by the existence of endometrial mucosa outside the uterine cavity, which causesinfertility, persistent aches, and a decline in women's quality of life. Both hormone therapies and nonhormone therapies, such as NSAIDs, are ineffective, generic categories of EM drugs. Endometriosis is a benign gynecological condition, yet it shares a number of features with cancer cells, including immune evasion, survival, adhesion, invasion, and angiogenesis. Several endometriosis-related signaling pathways are comprehensively reviewed in this article, including E2, NF-κB, MAPK, ERK, PI3K/Akt/mTOR, YAP, Wnt/β-catenin, Rho/ROCK, TGF-β, VEGF, NO, iron, cytokines and chemokines. To find and develop novel medications for the treatment of EM, it is essential to implicitly determine the molecular pathways that are disordered during EM development. Additionally, research on the shared pathways between EM and tumors can provide hypotheses or suggestions for endometriosis therapeutic targets.

Epigenetics, endometriosis and sex steroid receptors: An update on the epigenetic regulatory mechanisms of estrogen and progesterone receptors in patients with endometriosis

Endometriosis is a benign gynecological disease affecting ∼10% of reproductive-aged women and is defined as the presence of endometrial glands and stroma outside the uterine cavity. Endometriosis can cause a variety of health problems, from pelvic discomfort to catamenial pneumothorax, but it's mainly linked with severe and chronic pelvic pain, dysmenorrhea, and deep dyspareunia, as well as reproductive issues. The pathogenesis of endometriosis involves an endocrine dysfunction, with estrogen dependency and progesterone resistance, and inflammatory mechanism activation, together with impaired cell proliferation and neuroangiogenesis. The present chapter aims to discuss the main epigenetic mechanisms related to estrogen receptors (ERs) and progesterone receptors (PRs) in patients with endometriosis. There are numerous epigenetic mechanisms participating in endometriosis, regulating the expression of the genes encoding these receptors both indirectly, through the regulation of transcription factors, and directly, through DNA methylation, histone modifications, micro RNAs and long noncoding RNAs. This represents an open field of investigation, which may lead to important clinical implications such as the development of epigenetic drugs for the treatment of endometriosis and the identification of specific and early biomarkers for the disease.

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.

Endometriosis and inflammatory immune responses: Indian experience

Endometriosis is a public health disorder affecting ∼ 247 million women globally and ∼ 42 million women in India. Women with endometriosis suffer from dysmenorrhea, chronic pelvic pain, dyspareunia, dyschezia, fatigue, depression, and infertility leading to significant socioeconomic impact and morbidity. The etiology of endometriosis is not understood well even after 100 years of research. Currently, there is no permanent cure for endometriosis. The inflammatory immune response is one of the important features of etiopathogenesis of endometriosis and therefore understanding the inflammatory immune response would lead to a better understanding of this enigmatic disorder and may also lead to biomarker discovery for diagnosis of endometriosis. We investigated the autoimmune etiology of endometriosis in the Indian population. Using the proteomics approach, anti-endometrial antibodies (AEAs) were detected in Indian women with endometriosis [anti-endometrial antibodies - tropomyosin 3 (TPM3), stomatin-like protein2 (SLP-2), and tropomodulin 3 (TMOD3)]. The studies on AEAs provided a better understanding of autoimmune mechanisms in endometriosis. All three subtypes of endometriosis; superficial peritoneal, ovarian endometrioma, and deep infiltrating endometriosis were reported in Indian women. In this review, we discuss our experiences of the inflammatory immune response, autoimmunity, comorbidities, and clinical phenotypes in women with endometriosis in India.

Gut microbiota and microbiota-derived metabolites promotes endometriosis

Endometriosis is a pathological condition of the female reproductive tract characterized by the existence of endometrium-like tissue at ectopic sites, affecting 10% of women between the age 15 and 49 in the USA. However, currently there is no reliable non-invasive method to detect the presence of endometriosis without surgery and many women find hormonal therapy and surgery as ineffective in avoiding the recurrences. There is a lack of knowledge on the etiology and the factors that contribute to the development of endometriosis. A growing body of recent evidence suggests an association between gut microbiota and endometriosis pathophysiology. However, the direct impact of microbiota and microbiota-derived metabolites on the endometriosis disease progression is largely unknown. To understand the causal role of gut microbiota and endometriosis, we have implemented a novel model using antibiotic-induced microbiota-depleted (MD) mice to investigate the endometriosis disease progression. Interestingly, we found that MD mice showed reduced endometriotic lesion growth and, the transplantation of gut microbiota by oral gavage of feces from mice with endometriosis rescued the endometriotic lesion growth. Additionally, using germ-free donor mice, we indicated that the uterine microbiota is dispensable for endometriotic lesion growth in mice. Furthermore, we showed that gut microbiota modulates immune cell populations in the peritoneum of lesions-bearing mice. Finally, we found a novel signature of microbiota-derived metabolites that were significantly altered in feces of mice with endometriosis. Finally, we found one the altered metabolite, quinic acid promoted the survival of endometriotic epithelial cells in vitro and lesion growth in vivo, suggesting the disease-promoting potential of microbiota-derived metabolites. In summary, these data suggest that gut microbiota and microbiota-derived metabolome contribute to lesion growth in mice, possibly through immune cell adaptations. Of translational significance, these findings will aid in designing non-invasive diagnostics using stool metabolites for endometriosis.

Gene expression analysis in endometriosis: Immunopathology insights, transcription factors and therapeutic targets

Background

Endometriosis is recognized as an estrogen-dependent inflammation disorder, estimated to affect 8%-15% of women of childbearing age. Currently, the etiology and pathogenesis of endometriosis are not completely clear. Underlying mechanism for endometriosis is still under debate and needs further exploration. The involvement of transcription factors and immune mediations may be involved in the pathophysiological process of endometriosis, but the specific mechanism remains to be explored. This study aims to investigate the underlying molecular mechanisms in endometriosis.

Methods

The gene expression profile of endometriosis was obtained from the gene expression omnibus (GEO) database. Gene set variation analysis (GSVA) and gene set enrichment analysis (GSEA) were applied to the endometriosis GSE7305 datasets. Cibersort and MCP-counter were used to explore the immune response gene sets, immune response pathway, and immune environment. Differentially expressed genes (DEGs) were identified and screened. Common biological pathways were being investigated using the kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis. Transcription factors were from The Human Transcription Factors. The least absolute shrinkage and selection operator (Lasso) model identified four differential expressions of transcription factors (AEBP1, HOXB6, KLF2, and RORB). Their diagnostic value was calculated by receiver operating characteristic (ROC) curve analysis and validated in the validation cohort (GSE11691, GSE23339). By constructing the interaction network of crucial transcription factors, weighted gene coexpression network analysis (WGCNA) was used to search for key module genes. Metascape was used for enrichment analysis of essential module genes and obtained HOXB6, KLF2. The HOXB6 and KLF2 were further verified as the only two intersection genes according to Support Vector Machine Recursive Feature Elimination (SVM-RFE) and random forest models. We constructed ceRNA (lncRNA-miRNA-mRNA) networks with four potential transcription factors. Finally, we performed molecular docking for goserelin and dienogest with four transcription factors (AEBP1, HOXB6, KLF2, and RORB) to screen potential drug targets.

Results

Immune and metabolic pathways were enriched in GSVA and GSEA. In single sample gene set enrichment analysis (ssGSEA), most immune infiltrating cells, immune response gene sets, and immune response pathways are differentially expressed between endometriosis and non-endometriosis. Twenty-seven transcription factors were screened from differentially expressed genes. Most of the twenty-seven transcription factors were correlated with immune infiltrating cells, immune response gene sets and immune response pathways. Furthermore, Adipocyte enhancer binding protein 1 (AEBP1), Homeobox B6 (HOXB6), Kruppel Like Factor 2 (KLF2) and RAR Related Orphan Receptor B (RORB) were selected out from twenty-seven transcription factors. ROC analysis showed that the four genes had a high diagnostic value for endometriosis. In addition, KLF2 and HOXB6 were found to play particularly important roles in multiple modules (String, WGCNA, SVM-RFE, random forest) on the gene interaction network. Using the ceRNA network, we found that NEAT1 may regulate the expressions of AEBP1, HOXB6 and RORB, while X Inactive Specific Transcript (XIST) may control the expressions of HOXB6, RORB and KLF2. Finally, we found that goserelin and dienogest may be potential drugs to regulate AEBP1, HOXB6, KLF2 and RORB through molecular docking.

Conclusions

AEBP1, HOXB6, KLF2, and RORB may be potential biomarkers for endometriosis. Two of them, KLF2 and HOXB6, are critical molecules in the gene interaction network of endometriosis. Discovered by molecular docking, AEBP1, HOXB6, KLF2, and RORB are targets for goserelin and dienogest.

“Iron triangle” of regulating the uterine microecology: Endometrial microbiota, immunity and endometrium

The uterus is the core place for breeding new life. The balance and imbalance of uterine microecology can directly affect or even dominate the female reproductive health. Emerging data demonstrate that endometrial microbiota, endometrium and immunity play an irreplaceable role in regulating uterine microecology, forming a dynamic iron triangle relationship. Up to nowadays, it remains unclear how the three factors affect and interact with each other, which is also a frontier topic in the emerging field of reproductive tract microecology. From this new perspective, we aim to clarify the relationship and mechanism of the interaction of these three factors, especially their pairwise interactions. Finally, the limitations and future perspectives of the current studies are summarized. In general, these three factors have a dynamic relationship of mutual dependence, promotion and restriction under the physiological or pathological conditions of uterus, among which the regulatory mechanism of microbiota and immunity plays a role of bridge. These findings can provide new insights and measures for the regulation of uterine microecology, the prevention and treatment of endometrial diseases, and the further multi-disciplinary integration between microbiology, immunology and reproductive medicine.

Early growth response 1 transcription factor is essential for the pathogenic properties of human endometriotic epithelial cells

Although a non-malignant gynecological disorder, endometriosis displays some pathogenic features of malignancy, such as cell proliferation, migration, invasion and adaptation to hypoxia. Current treatments of endometriosis include pharmacotherapy and/or surgery, which are of limited efficacy and often associated with adverse side effects. Therefore, to develop more effective therapies to treat this disease, a broader understanding of the underlying molecular mechanisms that underpin endometriosis needs to be attained. Using immortalized human endometriotic epithelial and stromal cell lines, we demonstrate that the early growth response 1 (EGR1) transcription factor is essential for cell proliferation, migration and invasion, which represent some of the pathogenic properties of endometriotic cells. Genome-wide transcriptomics identified an EGR1-dependent transcriptome in human endometriotic epithelial cells that potentially encodes a diverse spectrum of proteins that are known to be involved in tissue pathologies. To underscore the utility of this transcriptomic data set, we demonstrate that carbonic anhydrase 9 (CA9), a homeostatic regulator of intracellular pH, is not only a molecular target of EGR1 but is also important for maintaining many of the cellular properties of human endometriotic epithelial cells that are also ascribed to EGR1. Considering therapeutic intervention strategies are actively being developed for EGR1 and CAIX in the treatment of other pathologies, we believe EGR1 and its transcriptome (which includes CA9) will offer not only a new conceptual framework to advance our understanding of endometriosis but will also furnish new molecular vulnerabilities to be leveraged as potential therapeutic options in the future treatment of endometriosis.

Hormonal treatments for endometriosis: The endocrine background

Endometriosis is a benign uterine disorder characterized by menstrual pain and infertility, deeply affecting women's health. It is a chronic disease and requires a long term management. Hormonal drugs are currently the most used for the medical treatment and are based on the endocrine pathogenetic aspects. Estrogen-dependency and progesterone-resistance are the key events which cause the ectopic implantation of endometrial cells, decreasing apoptosis and increasing oxidative stress, inflammation and neuroangiogenesis. Endometriotic cells express AMH, TGF-related growth factors (inhibin, activin, follistatin) CRH and stress related peptides. Endocrine and inflammatory changes explain pain and infertility, and the systemic comorbidities described in these patients, such as autoimmune (thyroiditis, arthritis, allergies), inflammatory (gastrointestinal/urinary diseases) and mental health disorders.The hormonal treatment of endometriosis aims to block of menstruation through an inhibition of hypothalamus-pituitary-ovary axis or by causing a pseudodecidualization with consequent amenorrhea, impairing the progression of endometriotic implants. GnRH agonists and antagonists are effective on endometriosis by acting on pituitary-ovarian function. Progestins are mostly used for long term treatments (dienogest, NETA, MPA) and act on multiple sites of action. Combined oral contraceptives are also used for reducing endometriosis symptoms by inhibiting ovarian function. Clinical trials are currently going on selective progesterone receptor modulators, selective estrogen receptor modulators and aromatase inhibitors. Nowadays, all these hormonal drugs are considered the first-line treatment for women with endometriosis to improve their symptoms, to postpone surgery or to prevent post-surgical disease recurrence. This review aims to provide a comprehensive state-of-the-art on the current and future hormonal treatments for endometriosis, exploring the endocrine background of the disease.

A Mouse Model of Endometriosis with Nanoparticle Labeling for In Vivo Photoacoustic Imaging

Endometriosis is a condition of the female reproductive tract characterized by endometrium-like tissue growing outside the uterus. Though it is a common cause of pelvic pain and infertility, there is currently no reliable noninvasive method to diagnose the presence of endometriosis without surgery, and the pathophysiological mechanisms that lead to the occurrence of symptoms require further inquiry. Due to patient heterogeneity and delayed diagnosis, animal models are commonly used to study the development of endometriosis, but these are costly due to the large number of animals needed to test various treatments and experimental conditions at multiple endpoints. Here, we describe a method for synthesis of multimodal imaging gold-fluorescein isothiocyanate (FITC) nanoparticles with preclinical application via induction of nanoparticle-labeled endometriosis-like lesions in mice. Labeling donor endometrial tissue fragments with gold-FITC nanoparticles prior to induction of endometriosis in recipients enables in vivo detection of the gold-labeled lesions with photoacoustic imaging. The same imaging method can be used to visualize embryos noninvasively in pregnant mice. Furthermore, the conjugated FITC dye on the gold nanoparticles allows easy isolation of labeled lesion tissue under a fluorescence dissection microscope. After dissection, the presence of gold-FITC nanoparticles and endometrium-like histology of lesions can be verified through fluorescence imaging, gold enhancement, and immunostaining. This method for in vivo imaging of endometriosis-like lesions and fluorescence-guided dissection will permit new experimental possibilities for the longitudinal study of endometriosis development and progression as well as endometriosis-related infertility.

Obesity Due to Steroid Receptor Coactivator-1 Deficiency Is Associated With Endocrine and Metabolic Abnormalities

CONTEXT

Genetic variants affecting the nuclear hormone receptor coactivator steroid receptor coactivator, SRC-1, have been identified in people with severe obesity and impair melanocortin signaling in cells and mice. As a result, obese patients with SRC-1 deficiency are being treated with a melanocortin 4 receptor agonist in clinical trials.

OBJECTIVE

Here, our aim was to comprehensively describe and characterize the clinical phenotype of SRC-1 variant carriers to facilitate diagnosis and clinical management.

METHODS

In genetic studies of 2462 people with severe obesity, we identified 23 rare heterozygous variants in SRC-1. We studied 29 adults and 18 children who were SRC-1 variant carriers and performed measurements of metabolic and endocrine function, liver imaging, and adipose tissue biopsies. Findings in adult SRC-1 variant carriers were compared to 30 age- and body mass index (BMI)-matched controls.

RESULTS

The clinical spectrum of SRC-1 variant carriers included increased food intake in children, normal basal metabolic rate, multiple fractures with minimal trauma (40%), persistent diarrhea, partial thyroid hormone resistance, and menorrhagia. Compared to age-, sex-, and BMI-matched controls, adult SRC-1 variant carriers had more severe adipose tissue fibrosis (46.2% vs 7.1% respectively, P = .03) and a suggestion of increased liver fibrosis (5/13 cases vs 2/13 in controls, odds ratio = 3.4), although this was not statistically significant.

CONCLUSION

SRC-1 variant carriers exhibit hyperphagia in childhood, severe obesity, and clinical features of partial hormone resistance. The presence of adipose tissue fibrosis and hepatic fibrosis in young patients suggests that close monitoring for the early development of obesity-associated metabolic complications is warranted.

Endometriosis-Associated Angiogenesis and Anti-angiogenic Therapy for Endometriosis

Endometriosis is a known estrogen-dependent inflammatory disease affecting reproductive-aged women. Common symptoms include pelvic pain, dysmenorrhea, dyspareunia, heavy menstrual bleeding, and infertility. The exact etiology of endometriosis is largely unknown, and, thus, the diagnosis and treatment of endometriosis are challenging. A complex interplay of many molecular mechanisms is thought to aid in the progression of endometriosis, most notably angiogenesis. This mini-review examines our current knowledge of the molecular etiology of endometriosis-associated angiogenesis and discusses anti-angiogenic therapy, in the blockade of endometriosis-associated angiogenesis, as potential non-hormonal therapy for the treatment of endometriosis.

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.

Molecular dysregulations underlying the pathogenesis of endometriosis

Endometriosis is a crippling disease characterized by the presence of endometrium-like tissue or scar outside the uterine cavity, commonly confined to the peritoneal and serosal surfaces of the pelvic organs. 10-15% of women in reproductive age are estimated to be affected by endometriosis. Most of these patients present with infertility and suffer from pelvic pain. The benign disease rarely progresses to malignancy. Regardless of its high prevalence, the pathogenesis of the disease is not fully understood. Treatment options for endometriosis are limited and are often based on a symptomatic approach. The unavailability of proper diagnostic approaches, fewer therapeutic options, and sparse understanding of molecular alterations are responsible for the continued disease burden. Exploring the molecular elements causing the pathogenesis of endometriosis may lead to a number of breakthroughs in the treatment of the illness, such as the discovery of new biomarkers for diagnosis and therapeutic targets that can be a guide to better prognosis and reduced recurrence. The goal of this review is to provide the reader a critical understanding of the disease by summarizing the genetic, immunological, hormonal, and epigenetic deregulations that support the molecular basis for development of endometriotic cyst, with a special focus on the study models needed to analyze these changes in the endometriotic microenvironment.

Molecular and Clinical Insights on the Complex Interaction between Oxidative Stress, Apoptosis, and Endobiota in the Pathogenesis of Endometriosis

Endometriosis (EMS) remains, to date, an intriguing and debilitating gynecological disorder that possesses a multifactorial substrate. Recent studies with the objective of elucidating its etiology highlighted the antagonistic effect of EMS on a multiple of processes involved in homeostasis. Although the current oxidative biomarkers clearly reveal the consequences induced by EMS, its implication in the associated inflammatory reactions could be much more complex. Besides the overproduction of reactive oxygen species (ROS) that leads to an exacerbated oxidative response, it also changes the normal expression of several pro-inflammatory modulators, reflected by the fluctuating activity of several pro- and anti-apoptotic mediators whose expression is impaired. In light of this topic, several studies elucidate the involvement of apoptosis in EMS, being brought controversial findings, even reports with no significant change. Further, some authors reported an abnormal expression of multiple genes that are crucial for the overall functionality of the female reproductive system. Cumulatively, it seems that the subsequent oxidative imbalance and apoptosis process impairment could further disrupt the normal removal of unnecessary biological products. Based on all gathered evidence, we could argue that the related stress state could determine human endobiota impairment, which could further participate in the inflammatory and main antioxidant enzyme changes occurring in EMS. Moreover, a correlation between endobiota integrity, inflammation, and oxidative stress (OS) was suggested in relation to the possible predisposition to pathogen determined infections.

Pharmaceuticals targeting signaling pathways of endometriosis as potential new medical treatment: A review

Endometriosis (EM) is defined as endometrial tissues found outside the uterus. Growth and development of endometriotic cells in ectopic sites can be promoted via multiple pathways, including MAPK/MEK/ERK, PI3K/Akt/mTOR, NF-κB, Rho/ROCK, reactive oxidative stress, tumor necrosis factor, transforming growth factor-β, Wnt/β-catenin, vascular endothelial growth factor, estrogen, and cytokines. The underlying pathophysiological mechanisms include proliferation, apoptosis, autophagy, migration, invasion, fibrosis, angiogenesis, oxidative stress, inflammation, and immune escape. Current medical treatments for EM are mainly hormonal and symptomatic, and thus the development of new, effective, and safe pharmaceuticals targeting specific molecular and signaling pathways is needed. Here, we systematically reviewed the literature focused on pharmaceuticals that specifically target the molecular and signaling pathways involved in the pathophysiology of EM. Potential drug targets, their upstream and downstream molecules with key aberrant signaling, and the regulatory mechanisms promoting the growth and development of endometriotic cells and tissues were discussed. Hormonal pharmaceuticals, including melatonin, exerts proapoptotic via regulating matrix metallopeptidase activity while nonhormonal pharmaceutical sorafenib exerts antiproliferative effect via MAPK/ERK pathway and antiangiogenesis activity via VEGF/VEGFR pathway. N-acetyl cysteine, curcumin, and ginsenoside exert antioxidant and anti-inflammatory effects via radical scavenging activity. Natural products have high efficacy with minimal side effects; for example, resveratrol and epigallocatechin gallate have multiple targets and provide synergistic efficacy to resolve the complexity of the pathophysiology of EM, showing promising efficacy in treating EM. Although new medical treatments are currently being developed, more detailed pharmacological studies and large sample size clinical trials are needed to confirm the efficacy and safety of these treatments in the near future.

Current Knowledge on Endometriosis Etiology: A Systematic Review of Literature

Objective

To review the mechanisms of endometriosis development, including those related to epigenetic mutations, cellular dysregulation, inflammatory processes, and oxidative stress.

Methods

A systematic literature review regarding current aspects of endometriosis etiology, genesis and development was performed using the PubMed, Google Scholar, and eLibrary databases. Keywords included endometriosis, etiology, development, genesis, associations and mechanisms. A multilingual search was performed.

Results

Several mechanisms underline the pathophysiological pathways for endometriosis development. Epigenetic mutations, external and internal influences, and chronic conditions have a significant impact on endometriosis development, survival and regulation. Several historically valid theories on endometriosis development were discussed, as well as updated findings.

Conclusion

Despite recent advances, fundamental problems in understanding endometriosis remain unresolved. The identification of unknown circulating epithelial progenitors or stem cells that are responsible for epithelial growth in both the endometrium and endometriotic foci seems to be the next step in solving these questions.

The efficacy and safety of Kuntai capsule combined with leuprorelin acetate in the treatment of endometriosis: A protocol for systematic review and meta-analysis

BACKGROUND

Endometriosis (EMS) is one of the common diseases in women, which seriously affects the quality of life of women. Leuprorelin acetate can control the development of EMS, but long-term use can cause perimenopausal symptoms in women. Clinical studies have shown that Kuntai capsule combined with leuprorelin acetate is effective in the treatment of EMS, which can relieve perimenopausal symptoms, but it lacks of evidence-based medical evidence. Therefore, this study aims to systematically evaluate the efficacy and safety of Kuntai capsule combined with leuprorelin acetate in the treatment of EMS.

METHODS

CNKI, VIP, Wanfang, Chinese Biomedical Literature Database, PubMed, The Cochrance Library, Embase, Web of Science, and other databases were searched by computer to collect randomized controlled trials of Kuntai capsule combined with leuprorelin acetate in the treatment of EMS. The retrieval time was from the establishment of the database to February 2021. Two researchers screened the literatures and extracted the data and meta-analysis was performed using RevMan 5.3 software.

RESULTS

This study evaluated the efficacy and safety of Kuntai capsule combined with leuprorelin acetate in the treatment of EMS by clinical effective rate, serum sex hormone levels estradiol, follicle-stimulating hormone, luteinizing hormone, visual analogue scale, Kupperman score and incidence of adverse reactions.

CONCLUSION

This study will provide reliable evidence-based evidence for the clinical application of Kuntai capsule combined with leuprorelin acetate in the treatment of EMS.

ETHICS AND DISSEMINATION

Private information from individuals will not be published. This systematic review also does not involve endangering participant rights. Ethical approval will not be required. The results may be published in a peer-reviewed journal or disseminated at relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/AZU47.

Emerging roles of steroid receptor coactivators in stromal cell responses

Tissue parenchyma is the functional unit of an organ and all of the remaining cells within that organ collectively make up the tissue stroma. The stroma includes fibroblasts, endothelial cells, immune cells, and nerves. Interactions between stromal and epithelial cells are essential for tissue development and healing after injury. These interactions are governed by growth factors, inflammatory cytokines and hormone signaling cascades. The steroid receptor coactivator (SRC) family of proteins includes three transcriptional coactivators that facilitate the assembly of multi-protein complexes to induce gene expression in response to activation of many cellular transcription factor signaling cascades. They are ubiquitously expressed and are especially critical for the developmental function of steroid hormone responsive tissues. The SRCs are overexpressed in multiple cancers including breast, ovarian, prostate and endometrial cancers. In this review, we focus on the role of the SRCs in regulating the functions of stromal cell components responsible for angiogenesis, inflammation and cell differentiation.

60S acidic ribosomal protein P1 (RPLP1) is elevated in human endometriotic tissue and in a murine model of endometriosis and is essential for endometriotic epithelial cell survival in vitro

Endometriosis is a female disease which is defined as the presence of ectopic endometrial tissue and is dependent on estrogen for its survival in these ectopic locations. Expression of the ribosomal protein large P1 (RPLP1) is associated with cell proliferation and invasion in several pathologies, but a role in the pathophysiology of endometriosis has not been explored. In this study, we aimed to evaluate the expression and function of RPLP1 with respect to endometriosis pathophysiology. RPLP1 protein was localised by immunohistochemistry (IHC) in eutopic and ectopic tissue from 28 subjects with confirmed endometriosis and from 20 women without signs or symptoms of the disease, while transcript levels were evaluated by qRT-PCR in 77 endometriotic lesions and 55 matched eutopic endometrial biopsies, and protein expression was evaluated using western blotting in 20 of these matched samples. To evaluate the mechanism for enhanced lesion expression of RPLP1, an experimental murine model of endometriosis was used and RPLP1 expression was localized using IHC. In vitro studies using an endometriosis cell line coupled with shRNA knockdown was used to demonstrate its role in cell survival. Expression of RPLP1 mRNA and protein were significantly higher in ectopic lesion tissue compared to paired eutopic endometrium and immunohistochemical localisation revealed predominant localisation to epithelial cells. This pattern of lesion RPLP1 was recapitulated in mice with experimentally induced endometriosis. Stable knockdown of RPLP1 protein resulted in a significant decrease in cell survival in vitro. These studies reveal that RPLP1 is associated with cell proliferation and/or survival and may play a role in the pathophysiology of endometriosis.

Kiwi Root Extract Inhibits the Development of Endometriosis in Mice by Downregulating Inflammatory Factors

Purpose

To determine whether the kiwi root extract inhibits the development of endometriosis in mice by suppressing inflammatory factors.

Materials and Methods

The mouse model of endometriosis was induced by surgery after which the mice were continuously injected with the drug for 14 days. On the 14^th day, the mice were sacrificed, and the peritoneal fluid was obtained for enzyme-linked immunosorbent assay. Endometrial ectopic tissue was weighed and analyzed by tissue immunochemistry, RT-PCR, western blotting, and gelatin zymography experiment.

Results

Kiwi root extract significantly reduced endometriotic lesion volume and downregulated the proinflammatory cytokines IL-6, IL-8, IL-1β, and TNF-α, as well as the angiogenic factor VEGF-A. It also inhibited the mRNA and protein expression of COX-1 and COX-2, IL-6, TGF-β1, EP₂ receptor, and ER-β in endometriotic lesions but did not affect the expression of MMP-9 and MMP-2.

Conclusions

Kiwi root extract could significantly inhibit the growth of surgery-induced endometriosis in mice. Our results suggest that the kiwi root extract may inhibit the development and progression of ectopic endometrium through disruption of neovascularization and reducing inflammation, which may be beneficial in treating this common gynecological disease.

Revisiting estrogen-dependent signaling pathways in endometriosis: Potential targets for non-hormonal therapeutics

Endometriosis is an estrogen-dependent gynecologic disease. Endometriotic cells survive in oxidative stress and hypoxic environments. The aim of this review is to reconsider new therapeutic strategies for endometriosis by focusing on estrogen signaling, ROS production and scavenging, and mitochondrial metabolism. Each keyword alone or in combination was used to search from PubMed and Embase by applying the filters of the title and the publication years between January 2000 and May 2020. Abnormal epigenetic marks of estrogen receptors (ERs) in endometriosis cause overexpression of ERβ, progesterone resistance, inflammation, anti-apoptosis, and mitochondrial metabolic modification. In addition to hormonal action, estrogen is involved in various functions such as mitochondrial biosynthesis and energy metabolism. Estrogen works with its downstream target genes to modulate mitochondrial gene expression, regulate ROS production, and affect mitochondrial biology, including ATP production, antioxidant defenses, mitochondrial biosynthesis, quality control, and energy-transducing capacity. Endometriosis can shift mitochondrial metabolism from oxidative phosphorylation to aerobic glycolysis. This metabolic conversion suppresses ROS production and thus activates the survival signal of endometriotic cells. Therefore, molecules associated with aerobic glycolysis and mitochondrial metabolism are considered therapeutic targets for endometriosis. In conclusion, estrogen downstream target genes involved in mitochondrial metabolic biosynthesis may be potential targets for non-hormonal treatment of endometriosis.

Lipoxin A4 inhibits the development of endometriosis in a mouse model by suppressing local estradiol synthesis

We investigated whether lipoxin A4 (LXA4) inhibits the development of endometriosis by suppressing local estradiol synthesis. An endometriosis mouse model was constructed by surgical transplantation to subcutanous tissue sites. The treatment group received daily injections of LXA4 (10 μg/Kg) for 21days after which lesions were recovered. We measured 17β-HSD1, 17β-HSD2, CYP11A1, CYP19A1, CYP17A1, and estrogen receptor mRNA expression levels using real-time RT-PCR. In addition, immunohistochemistry was performed to determine protein expression and localization. After LXA4 administration, the volume of endometrial lesions was significantly reduced. Administration of LXA4 resulted in a more rudimentary architecture with a reduced number of developed glands surrounded by a small amount of stroma. LXA4 downregulated the mRNA and protein expression levels of 17β-HSD1, CYP11A1, CYP19A1, CYP17A1, ERα, and ERβ. Furthermore, LXA4 downregulated the expression of ERβ, aromatase expression, and 17β-HSD1 enzyme activity, which affected local estradiol production, resulting in reduced endometriosis. Results from our endometriosis mouse model showed that treatment with LXA4 reduced expression of enzymes and receptors associated or implicated with estrogen-dependent regulation of extra-uterine tissue. We believe that LXA4 has a potential therapeutic value for the treatment of endometriosis.

Cancer-associated mutations in endometriosis: shedding light on the pathogenesis and pathophysiology

BACKGROUND

Endometriosis is a benign gynaecological disease. Thus, it came as a complete surprise when it was reported recently that the majority of deep endometriosis lesions harbour somatic mutations and a sizeable portion of them contain known cancer-associated mutations (CAMs). Four more studies have since been published, all demonstrating the existence of CAMs in different subtypes of endometriosis. While the field is still evolving, the confirmation of CAMs has raised many questions that were previously overlooked.

OBJECTIVE AND RATIONALE

A comprehensive overview of CAMs in endometriosis has been produced. In addition, with the recently emerged understanding of the natural history of endometriotic lesions as well as CAMs in normal and apparently healthy tissues, this review attempts to address the following questions: Why has there been such a wild discrepancy in reported mutation frequencies? Why does ectopic endometrium have a higher mutation rate than that of eutopic endometrium? Would the presence of CAMs in endometriotic lesions increase the risk of cancer to the bearers? Why do endometriotic epithelial cells have much higher mutation frequencies than their stromal counterpart? What clinical implications, if any, do the CAMs have for the bearers? Do these CAMs tell us anything about the pathogenesis and/or pathophysiology of endometriosis?

SEARCH METHODS

The PubMed database was searched, from its inception to September 2019, for all papers in English using the term 'endometriosis and CAM', 'endometriosis and cancer-driver mutation', 'somatic mutations', 'fibrosis', 'fibrosis and epigenetic', 'CAMs and tumorigenesis', 'somatic mutation and normal tissues', 'oestrogen receptor and fibrosis', 'oxidative stress and fibrosis', 'ARID1A mutation', and 'Kirsten rat sarcoma mutation and therapeutics'. All retrieved papers were read and, when relevant, incorporated into the review results.

OUTCOMES

Seven papers that identified CAMs in endometriosis using various sequencing methods were retrieved, and their results were somewhat different. Yet, it is apparent that those using microdissection techniques and more accurate sequencing methods found more CAMs, echoing recent discoveries that apparently healthy tissues also harbour CAMs as a result of the replicative aging process. Hence endometriotic lesions, irrespective of subtype, if left intact, would generate CAMs as part of replicative aging, oxidative stress and perhaps other factors yet to be identified and, in some rare cases, develop cancer. The published data still are unable to paint a clear picture on pathogenesis of endometriosis. However, since endometriotic epithelial cells have a higher turnover than their stromal counterpart due to cyclic bleeding, and since the endometriotic stromal component can be formed by refresh influx of mesenchymal cells through epithelial-mesenchymal transition, endothelial-mesenchymal transition, mesothelial-mesenchymal transition and other processes as well as recruitment of bone-marrow-derived stem cells and outflow due to smooth muscle metaplasia, endometriotic epithelial cells have much higher mutation frequencies than their stromal counterpart. The epithelial and stromal cellular components develop in a dependent and co-evolving manner. Genes involved in CAMs are likely to be active players in lesional fibrogenesis, and hyperestrogenism and oxidative stress are likely drivers of both CAMs and fibrogenesis. Finally, endometriotic lesions harbouring CAMs would conceivably be more refractory to medical treatment, due, in no small part, to their high fibrotic content and reduced vascularity and cellularity.

WIDER IMPLICATIONS

The accumulating data on CAMs in endometriosis have shed new light on the pathogenesis and pathophysiology of endometriosis. They also suggest new challenges in management. The distinct yet co-evolving developmental trajectories of endometriotic stroma and epithelium underscore the importance of the lesional microenvironment and ever-changing cellular identity. Mutational profiling of normal endometrium from women of different ages and reproductive history is needed in order to gain a deeper understanding of the pathogenesis. Moreover, one area that has conspicuously received scant attention is the epigenetic landscape of ectopic, eutopic and normal endometrium.

Increased expression of epithelial cell adhesion molecule and its possible role in epithelial-mesenchymal transition in endometriosis

AIM

To study the involvement and interrelationship of epithelial cell adhesion molecule (EpCAM) and epithelial-mesenchymal transition (EMT) in endometriosis.

METHODS

Samples from 114 patients undergoing endometrial biopsy or operation for endometriosis and 23 premenopausal women undergoing endometrial biopsy for non-endometriotic benign disease. Immunohistochemistry was used to detect expression level of EpCAM, E-cadherin and N-cadherin in endometrium from patients with (n = 24) and without endometriosis (n = 23), and in lesions from bowel (n = 46), peritoneal (n = 20) and ovarian (n = 24) endometriosis.

RESULTS

There was no significant difference in the expression level of EpCAM, E-cadherin and N-cadherin, respectively, between endometrium from women with and without endometriosis (P > 0.05). There was also no significant difference in the expression level of EpCAM, E-cadherin and N-cadherin, respectively, among lesions from the bowel, peritoneal and ovarian endometriosis (P > 0.05). We found that the immunoreactivity of endometriotic epithelial cells to EpCAM and N-cadherin was significantly higher than that of eutopic endometrium, but decreased to E-cadherin (P < 0.05). According to the expression level of EpCAM, the expression level of E-Cadherin was significantly lower in endometriotic lesions with EpCAM expression above the mean level compared with that of endometriotic lesions with EpCAM expression below mean level, while the expression level of N-cadherin was contrary (P < 0.001). EpCAM staining level was negatively correlated with E-cadherin but positively correlated with N-cadherin (P < 0.001).

CONCLUSIONS

These data suggest that overexpression of EpCAM, accompanied by an EMT, might be involved in endometriosis. EMT may be induced by the overexpression of EpCAM, thus promoting the development of endometriosis, which needs future studies to confirm for the pathogenesis of endometriosis.

Endometriosis and nuclear receptors

BACKGROUND

Endometriosis is recognized as a steroid-dependent disorder; however, the precise roles of nuclear receptors (NRs) in steroid responsiveness and other signaling pathways are not well understood.

OBJECTIVE AND RATIONALE

Over the past several years, a number of paradigm-shifting breakthroughs have occurred in the area of NRs in endometriosis. We review and clarify new information regarding the mechanisms responsible for: (i) excessive estrogen biosynthesis, (ii) estrogen-dependent inflammation, (iii) defective differentiation due to progesterone resistance and (iv) enhanced survival due to deficient retinoid production and action in endometriosis. We emphasize the roles of the relevant NRs critical for these pathological processes in endometriosis.

SEARCH METHODS

We conducted a comprehensive search using PubMed for human, animal and cellular studies published until 2018 in the following areas: endometriosis; the steroid and orphan NRs, estrogen receptors alpha (ESR1) and beta (ESR2), progesterone receptor (PGR), steroidogenic factor-1 (NR5A1) and chicken ovalbumin upstream promoter-transcription factor II (NR2F2); and retinoids.

OUTCOMES

Four distinct abnormalities in the intracavitary endometrium and extra-uterine endometriotic tissue underlie endometriosis progression: dysregulated differentiation of endometrial mesenchymal cells, abnormal epigenetic marks, inflammation activated by excess estrogen and the development of progesterone resistance. Endometriotic stromal cells compose the bulk of the lesions and demonstrate widespread epigenetic abnormalities. Endometriotic stromal cells also display a wide range of abnormal NR expression. The orphan NRs NR5A1 and NR2F2 compete to regulate steroid-synthesizing genes in endometriotic stromal cells; NR5A1 dominance gives rise to excessive estrogen formation. Endometriotic stromal cells show an abnormally low ESR1:ESR2 ratio due to excessive levels of ESR2, which mediates an estrogen-driven inflammatory process and prostaglandin formation. These cells are also deficient in PGR, leading to progesterone resistance and defective retinoid synthesis. The pattern of NR expression, involving low ESR1 and PGR and high ESR2, is reminiscent of uterine leiomyoma stem cells. This led us to speculate that endometriotic stromal cells may display stem cell characteristics found in other uterine tissues. The biologic consequences of these abnormalities in endometriotic tissue include intense inflammation, defective differentiation and enhanced survival.

WIDER IMPLICATIONS

Steroid- and other NR-related abnormalities exert genome-wide biologic effects via interaction with defective epigenetic programming and enhance inflammation in endometriotic stromal cells. New synthetic ligands, targeting PGR, retinoic acid receptors and ESR2, may offer novel treatment options.

Bis-Indole-Derived Nuclear Receptor 4A1 (NR4A1, Nur77) Ligands as Inhibitors of Endometriosis

Endometriosis is an inflammatory disease that primarily affects women during their reproductive years, and since current hormonal therapies are of concern, new hormone-independent treatment regimens are needed. The orphan nuclear receptor 4A1 (NR4A1, Nur77) is expressed in patient-derived (stromal) endometriotic cells and also epithelial cell lines, and we observed that knockdown of NR4A1 in patient-derived ectopic endometrium-isolated ovarian endometrioma (ESECT)-7 and ESECT-40 cells decreased cell proliferation and induced apoptosis. Moreover, the treatment of these cells with bis-indole derived NR4A1 ligands 1,1-bis(3'-indolyl)-1-(p-hydroxyphenyl)methane (DIM-C-pPhOH) and its buttressed 3-chloro-5-methoxy analog (DIM-C-pPhOH-3-Cl-5-OCH3) inhibited cell growth and induced apoptosis and related genes. The compounds exhibit NR4A1 antagonist activities in both functional and transactivation assays whereas these effects were not observed in normal endometrial cells. We also observed that NR4A1 knockdown and treatment with NR4A1 antagonists decreased fibrosis, α-smooth muscle actin, and related pro-fibrotic genes in ESECT-7 and ESECT-40 cells, and similar results were observed in epithelial-derived endometriotic cell lines. Moreover, in an endometriosis mouse model with auto-transplantation and also in severe combined immune deficiency mice transplanted with human endometriotic cells treatment with 25 mg/kg/day DIM-C-pPhOH-3-Cl-5-OCH3 significantly inhibited growth and expansion of endometriotic lesions. Thus, bis-indole-derived NR4A1 ligands represent a novel class of drugs as nonhormonal therapy for endometriosis.

Epithelial Cells in Endometriosis and Adenomyosis Upregulate STING Expression

In response to cytosolic DNA, stimulator of interferon gene (STING) initiates and orchestrates host's innate immunity by inducing type I interferon. Since endometriosis is a chronic inflammatory disorder, we sought to determine whether STING pathway is activated in ectopic endometrium in comparison to eutopic endometrium. Immunohistochemistry was employed in evaluating the expression levels of STING in normal endometrium, endometriosis, and adenomyosis. The density of CD45+ intraepithelial lymphocytes was correlated with STING expression levels. A total of 39 cases of endometriosis and/or adenomyosis with normal endometrium were analyzed. Among them, 32 had adenomyosis, 26 had endometriosis, and 19 have both lesions. STING protein expression is mainly evident in the cytoplasm of epithelial cells but much less in stromal cells. Based on H-score, we found that the STING expression levels were significantly higher in the epithelial cells of adenomyosis and endometriosis than in eutopic endometrium (132.7 ± 12.20, 119.6 ± 12.57 vs. 19.74 ± 5.96, p < 0.0001). There was no significant difference in STING expression level between endometriosis and adenomyosis. More intraepithelial lymphocytes were detected in endometriosis and adenomyosis lesions than endometrium (5.60 ± 0.70%, 4.95 ± 0.54% vs. 1.25 ± 0.12%, p < 0.0001). A positive correlation between STING expression and intraepithelial lymphocytic infiltrate was observed (p < 0.0001). In summary, STING was upregulated in the epithelium of ectopic endometrium as compared to eutopic endometrium. Its expression levels correlate with the degree of intraepithelial lymphocyte infiltration, suggesting a role in promoting chronic inflammation of ectopic endometrium.

The Origin and Pathogenesis of Endometriosis

Recent molecular genetic findings on endometriosis and normal endometrium suggest a modified model in which circulating epithelial progenitor or stem cells intended to regenerate uterine endometrium after menstruation may become overreactive and trapped outside the uterus. These trapped epithelium-committed progenitor cells form nascent glands through clonal expansion and recruit polyclonal stromal cells, leading to the establishment of deep infiltrating endometriosis. Once formed, the ectopic tissue becomes subject to immune surveillance, resulting in chronic inflammation. The inflammatory response orchestrated by nuclear factor-κB signaling is exacerbated by aberrations in the estrogen receptor-β and progesterone receptor pathways, which are also affected by local inflammation, forming a dysregulated inflammation-hormonal loop. Glandular epithelium within endometriotic tissue harbors cancer-associated mutations that are frequently detected in endometriosis-related ovarian cancers. In this review, we summarize recent advances that have illuminated the origin and pathogenesis of endometriosis and have provided new avenues for research that promise to improve the early diagnosis and management of endometriosis.

Microgravity inhibits decidualization via decreasing Akt activity and FOXO3a expression in human endometrial stromal cells

Decidualization is characterized by the differentiation of endometrial stromal cells (eSCs), which is critical for embryo implantation and maintenance of pregnancy. In the present study, we investigated the possible effect of simulated microgravity (SM) on the process of proliferation and in vitro decidualization using primary human eSCs. Exposure to SM for 36 h decreased the proliferation and migration of eSCs significantly, without inducing cell death and changes in cell cycle progression. The phosphorylation of Akt decreased under SM conditions in human eSCs, accompanied by a simultaneous decrease in the level of matrix metalloproteinase (MMP)-2 and FOXO3a. Treatment with Akti, an Akt inhibitor, decreased MMP-2 expression, but not FOXO3a expression. The decreased level of FOXO3a under SM conditions impeded autophagic flux by reducing the levels of autophagy-related genes. In addition, pre-exposure of eSCs to SM significantly inhibited 8-Br-cAMP induced decidualization, whereas restoration of the growth status under SM conditions by removing 8-Br-cAMP remained unchanged. Treatment of human eSCs with SC-79, an Akt activator, restored the reduced migration of eSCs and decidualization under SM conditions. In conclusion, exposure to SM inhibited decidualization in eSCs by decreasing proliferation and migration through Akt/MMP and FOXO3a/autophagic flux.

Progesterone and Estrogen Signaling in the Endometrium: What Goes Wrong in Endometriosis?

In the healthy endometrium, progesterone and estrogen signaling coordinate in a tightly regulated, dynamic interplay to drive a normal menstrual cycle and promote an embryo-receptive state to allow implantation during the window of receptivity. It is well-established that progesterone and estrogen act primarily through their cognate receptors to set off cascades of signaling pathways and enact large-scale gene expression programs. In endometriosis, when endometrial tissue grows outside the uterine cavity, progesterone and estrogen signaling are disrupted, commonly resulting in progesterone resistance and estrogen dominance. This hormone imbalance leads to heightened inflammation and may also increase the pelvic pain of the disease and decrease endometrial receptivity to embryo implantation. This review focuses on the molecular mechanisms governing progesterone and estrogen signaling supporting endometrial function and how they become dysregulated in endometriosis. Understanding how these mechanisms contribute to the pelvic pain and infertility associated with endometriosis will open new avenues of targeted medical therapies to give relief to the millions of women suffering its effects.

Endometriosis

Pelvic endometriosis is a complex syndrome characterized by an estrogen-dependent chronic inflammatory process that affects primarily pelvic tissues, including the ovaries. It is caused when shed endometrial tissue travels retrograde into the lower abdominal cavity. Endometriosis is the most common cause of chronic pelvic pain in women and is associated with infertility. The underlying pathologic mechanisms in the intracavitary endometrium and extrauterine endometriotic tissue involve defectively programmed endometrial mesenchymal progenitor/stem cells. Although endometriotic stromal cells, which compose the bulk of endometriotic lesions, do not carry somatic mutations, they demonstrate specific epigenetic abnormalities that alter expression of key transcription factors. For example, GATA-binding factor-6 overexpression transforms an endometrial stromal cell to an endometriotic phenotype, and steroidogenic factor-1 overexpression causes excessive production of estrogen, which drives inflammation via pathologically high levels of estrogen receptor-β. Progesterone receptor deficiency causes progesterone resistance. Populations of endometrial and endometriotic epithelial cells also harbor multiple cancer driver mutations, such as KRAS, which may be associated with the establishment of pelvic endometriosis or ovarian cancer. It is not known how interactions between epigenomically defective stromal cells and the mutated genes in epithelial cells contribute to the pathogenesis of endometriosis. Endometriosis-associated pelvic pain is managed by suppression of ovulatory menses and estrogen production, cyclooxygenase inhibitors, and surgical removal of pelvic lesions, and in vitro fertilization is frequently used to overcome infertility. Although novel targeted treatments are becoming available, as endometriosis pathophysiology is better understood, preventive approaches such as long-term ovulation suppression may play a critical role in the future.

Antibiotic therapy with metronidazole reduces endometriosis disease progression in mice: a potential role for gut microbiota

STUDY QUESTION

Does altering gut microbiota with antibiotic treatment have any impact on endometriosis progression?

SUMMARY ANSWER

Antibiotic therapy reduces endometriosis progression in mice, possibly by reducing specific gut bacteria.

WHAT IS KNOWN ALREADY

Endometriosis, a chronic condition causing abdominal pain and infertility, afflicts up to 10% of women between the ages of 25 and 40, ~5 million women in the USA. Current treatment strategies, including hormone therapy and surgery, have significant side effects and do not prevent recurrences. We have little understanding of why some women develop endometriosis and others do not.

STUDY DESIGN, SIZE, DURATION

Mice were treated with broad-spectrum antibiotics or metronidazole, subjected to surgically-induced endometriosis and assayed after 21 days.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The volumes and weights of endometriotic lesions and histological signatures were analysed. Proliferation and inflammation in lesions were assessed by counting cells that were positive for the proliferation marker Ki-67 and the macrophage marker Iba1, respectively. Differences in faecal bacterial composition were assessed in mice with and without endometriosis, and faecal microbiota transfer studies were performed.

MAIN RESULTS AND THE ROLE OF CHANCE

In mice treated with broad-spectrum antibiotics (vancomycin, neomycin, metronidazole and ampicillin), endometriotic lesions were significantly smaller (~ 5-fold; P < 0.01) with fewer proliferating cells (P < 0.001) than those in mice treated with vehicle. Additionally, inflammatory responses, as measured by the macrophage marker Iba1 in lesions and IL-1β, TNF-α, IL-6 and TGF-β1 in peritoneal fluid, were significantly reduced in mice treated with broad-spectrum antibiotics (P < 0.05). In mice treated with metronidazole only, but not in those treated with neomycin, ectopic lesions were significantly (P < 0.001) smaller in volume than those from vehicle-treated mice. Finally, oral gavage of faeces from mice with endometriosis restored the endometriotic lesion growth and inflammation (P < 0.05 and P < 0.01, respectively) in metronidazole-treated mice.

LARGE-SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

These findings are from a mouse model of surgically-induced endometriosis. Further studies are needed to determine the mechanism by which gut bacteria promote inflammation, identify bacterial genera or species that promote disease progression and assess the translatability of these findings to humans.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that gut bacteria promote endometriosis progression in mice. This finding if translated to humans, could aid in the development of improved diagnostic tools and personalised treatment strategies.

STUDY FUNDING AND COMPETING INTEREST(S)

This work was funded, in part, by: a National Institutes of Health (NIH)/ National Institute of Child Health and Human Development (NICHD) grant (R00HD080742) to RK; Washington University School of Medicine start-up funds to RK; an Endometriosis Foundation of America Research Award to R.K.; and an NIH/NICHD grant (R01HD091218) to IUM. The authors report no conflict of interest.

Retinoid signaling controlled by SRC-2 in decidualization revealed by transcriptomics

Establishment of a successful pregnancy requires not only implantation of a healthy embryo into a receptive uterus but also progesterone receptor (PGR)-dependent transformation of endometrial stromal cells (ESCs) into specialized decidual cells. Decidual cells support the developing embryo and are critical for placentation. We have previously shown that a known transcriptional coregulator of the PGR, steroid receptor coactivator-2 (SRC-2), is a critical driver of endometrial decidualization in both human and mouse endometrium. However, the full spectrum of genes transcriptionally controlled by SRC-2 in decidualizing ESCs has not been identified. Therefore, using an RNA- and chromatin immunoprecipitation-sequencing approach, we have identified the transcriptome of decidualizing human ESCs (hESCs) that requires SRC-2. We revealed that the majority of hESC genes regulated by SRC-2 are associated with decidualization. Over 50% of SRC-2-regulated genes are also controlled by the PGR. While ontology analysis showed that SRC-2-dependent genes are functionally linked to signaling processes known to underpin hESC decidualization, cell membrane processes were significantly enriched in this analysis. Follow-up studies showed that retinoid signaling is dependent on SRC-2 during hESC decidualization. Specifically, SRC-2 is required for full induction of the retinol transporter, stimulated by retinoic acid 6 (STRA6), which is essential for hESC decidualization. Together our findings show that a critical subset of genes transcriptionally reprogramed by PGR during hESC decidualization requires SRC-2. Among the multiple genes, pathways and networks that are dependent on SRC-2 during hESC decidualization, first-line analysis supports a critical role for this coregulator in maintaining retinoid signaling during progesterone-driven decidualization.

The Endometriotic Tumor Microenvironment in Ovarian Cancer

Women with endometriosis are at increased risk of developing ovarian cancer, specifically ovarian endometrioid, low-grade serous, and clear-cell adenocarcinoma. An important clinical caveat to the association of endometriosis with ovarian cancer is the improved prognosis for women with endometriosis at time of ovarian cancer staging. Whether endometriosis-associated ovarian cancers develop from the molecular transformation of endometriosis or develop because of the endometriotic tumor microenvironment remain unknown. Additionally, how the presence of endometriosis improves prognosis is also undefined, but likely relies on the endometriotic microenvironment. The unique tumor microenvironment of endometriosis is composed of epithelial, stromal, and immune cells, which adapt to survive in hypoxic conditions with high levels of iron, estrogen, and inflammatory cytokines and chemokines. Understanding the unique molecular features of the endometriotic tumor microenvironment may lead to impactful precision therapies and/or modalities for prevention. A challenge to this important study is the rarity of well-characterized clinical samples and the limited model systems. In this review, we will describe the unique molecular features of endometriosis-associated ovarian cancers, the endometriotic tumor microenvironment, and available model systems for endometriosis-associated ovarian cancers. Continued research on these unique ovarian cancers may lead to improved prevention and treatment options.

The Immunopathophysiology of Endometriosis

Endometriosis is a chronic, inflammatory, estrogen-dependent disease characterized by the growth of endometrial tissue outside of the uterine cavity. Although the etiology of endometriosis remains elusive, immunological dysfunction has been proposed as a critical facilitator of ectopic lesion growth following retrograde menstruation of endometrial debris. However, it is not clear whether this immune dysfunction is a cause or consequence of endometriosis. Thus, here we provide in-depth insights into our current understanding of the immunopathophysiology of endometriosis and highlight challenges and opportunities for future research. With the explosion of successful immune-based therapies targeting various chronic inflammatory conditions, it is crucial to determine whether immune dysfunction can be therapeutically targeted in endometriosis.

Transcription factor 21 regulates expression of ERβ and SF-1 via upstream stimulatory factor-2 in endometriotic tissues

Steroidogenic factor-1 (SF-1, encoded by NR5A1) and estrogen receptor beta (ERβ, encoded by ESR2), which are highly expressed in endometriotic stromal cells (ESCs), contribute to the pathogenesis of endometriosis, but the regulation mechanism remains largely unknown. Transcription factor 21 (TCF21) belongs to the helix-loop-helix (bHLH) family characterized by regulating gene expression via binding to E-box element. Here, we attempted to determine the molecular mechanism of TCF21 on SF-1 and ERβ expression in endometriosis. We found that TCF21 expression in ESCs was higher than that in endometrial stromal cells (EMs), and positively correlated with SF-1 and ERβ expression in ESCs. Since the importance of E-box element for NR5A1 promoter activity has been previously reported, we performed site-mutation and luciferase assay, revealing that the E-box sequence in the ESR2 promoter is also a critical element modulating ERβ expression. Upstream stimulatory factor 2 (USF2) is another bHLH factor implicated in transcriptional regulation. Further analyses elucidated that it is not TCF21, but USF2 exhibited higher binding affinities in ESCs to NR5A1 and ESR2 promoters than in EMs. Additionally, TCF21 knockdown significantly decreased the binding activities of USF2 to NR5A1 and ESR2 promoters via disruption of the TCF21-USF2 complex. Meanwhile, manipulating TCF21 expression significantly affected MMP9 and cyclinD1 expression, as wells as proliferation and invasion of ESCs. Moreover, TCF21 depletion in endometriotic xenografts reduced SF-1 and ERβ expression, abrogating ectopic lesion growth in mice. Cumulatively, a critical role of TCF21 in the pathogenesis of endometriosis is demonstrated, suggesting a potential druggable target for future therapy.

Bufalin suppresses endometriosis progression by inducing pyroptosis and apoptosis

The steroid receptor coactivator (SRC)-1 isoform/estrogen receptor (ER)-β axis has an essential role in endometriosis progression. In this context, therefore, bufalin was employed as a 'tool compound' to evaluate inhibitors of SRC in alternative endometriosis treatment. Bufalin effectively suppressed the growth of primary human endometrial stroma cells isolated from endometriosis patients compared to women without endometriosis and immortalized human endometrial epithelial and stromal cells expressing the SRC-1 isoform compared to their parental cells in vitroIn vivo, compared to the vehicle, bufalin treatment significantly suppressed the growth of endometriotic lesions in mice with surgically induced endometriosis because bufalin disrupted the functional axis of SRC-1 isoform/ERβ by increasing SRC-1 isoform protein stability, hyperactivating the transcriptional activity of the SRC-1 isoform and degrading the ERβ protein by proteasome 26S subunit, non-ATPase 2 in endometriotic lesions. Bufalin treatment elevated the apoptosis signaling in epithelial cells of endometriotic lesions. In stromal cells of endometriotic lesions, bufalin treatment increased the levels of pyroptosis markers (caspase 1 and the active form of interleukin 1β) and reduced proliferation. In addition, bufalin treatment increased the expression levels of endoplasmic reticulum-stress (ERS) markers (PKR-like ER kinase, protein disulfide isomerase and binding immunoglobulin) in endometriotic lesions. Collectively, the bufalin-induced disruption of the SRC-1 isoform/ERβ axis might induce apoptosis, pyroptosis and ERS signaling in endometriotic lesions, causing the suppression of endometriosis. Therefore, future generations of SRC-modulators could be employed as an alternative medical approach for endometriosis treatment.

The ginsenoside PPD exerts anti-endometriosis effects by suppressing estrogen receptor-mediated inhibition of endometrial stromal cell autophagy and NK cell cytotoxicity

Endometriosis (EMS) is an estrogen-dependent gynecological disease with a low autophagy level of ectopic endometrial stromal cells (eESCs). Impaired NK cell cytotoxic activity is involved in the clearance obstruction of the ectopic endometrial tissue in the abdominopelvic cavity. Protopanaxadiol (PPD) and protopanaxatriol (PPT) are two metabolites of ginsenosides, which have profound biological functions, such as anti-cancer activities. However, the role and mechanism of ginsenosides and metabolites in endometriosis are completely unknown. Here, we found that the compounds PPD, PPT, ginsenoside-Rg3 (G-Rg3), ginsenoside-Rh2 (G-Rh2), and esculentoside A (EsA) led to significant decreases in the viability of eESCs, particularly PPD (IC50 = 30.64 µM). In vitro and in vivo experiments showed that PPD promoted the expression of progesterone receptor (PR) and downregulated the expression of estrogen receptor α (ERα) in eESCs. Treatment with PPD obviously induced the autophagy of eESCs and reversed the inhibitory effect of estrogen on eESC autophagy. In addition, eESCs pretreated with PPD enhanced the cytotoxic activity of NK cells in response to eESCs. PPD decreased the numbers and suppressed the growth of ectopic lesions in a mouse EMS model. These results suggest that PPD plays a role in anti-EMS activation, possibly by restricting estrogen-mediated autophagy regulation and enhancing the cytotoxicity of NK cells. This result provides a scientific basis for potential therapeutic strategies to treat EMS by PPD or further structural modification.

Genetic Variation at Chromosome 2q13 and Its Potential Influence on Endometriosis Susceptibility Through Effects on the IL-1 Family

Endometriosis is characterized by the growth of epithelial and stromal cells outside the uterine cavity. It has a complex etiology and affects ∼10% of reproductive age women. It is accompanied by a chronic inflammatory response with substantial evidence to indicate genetic susceptibility. The causal genes and their pathways leading to endometriosis, however, are still unknown. Recently, genomewide association studies on endometriosis identified 14 genomic risk loci in women of European and Japanese ancestry. It is becoming increasingly clear that these risk regions are intergenic and thus contribute to disease susceptibility through regulatory mechanisms, most likely mediated through regulation of genes within a restricted distance from the risk variants. One endometriosis risk locus has been detected at chromosome 2q13 within an inflammatory-rich region of gene transcripts and thus may play a role in the inflammation component of the disease. We carried out detailed analysis of the genomic region 250 kb on either side of sentinel SNP rs10167914 and identified 21 transcripts which contained 6 interleukin (IL)-1 family genes, 3 previously reported coding genes that have a relationship to inflammation, 4 novel coding, or pseudogenes, and 8 noncoding RNA transcripts. Through an extensive literature search, we examined the roles these genes and their resultant proteins play in endometriosis pathogenesis. The results suggest alteration in the expression the IL-1 family transcripts either alone or as a complex milieu could have a significant influence on endometriosis and should be prioritized for future study on the implications of inflammation on endometriotic lesions.

Dysfunctional signaling underlying endometriosis: current state of knowledge

Endometriosis is defined as the presence of endometrial tissue outside the uterine cavity. It affects approximately 5-10% of women of reproductive age. Endometriosis is associated with dysmenorrhea, dyspareunia and, often, severe pelvic pain. In addition to pain, women with endometriosis often experience infertility. Defining the molecular etiology of endometriosis is a significant challenge for improving the quality of women's lives. Unfortunately, the pathophysiology of endometriosis is not well understood. Here, we summarize the potential causative factors of endometriosis in the following three categories: (1) dysregulation of immune cells in the peritoneal fluid and endometriotic lesions; (2) alteration of apoptotic signaling in retrograde menstrual tissue and cytotoxic T cells involved in endometriosis progression and (3) dysregulation of oxidative stress. Determining the molecular etiology of these dysregulated cellular signaling pathways should provide crucial clues for understanding initiation and progression of endometriosis. Moreover, improved understanding should suggest new molecular therapeutic targets that could improve the specificity of endometriosis treatments and reduce the side effects associated with current approaches.

Calpain7 impairs embryo implantation by downregulating β3-integrin expression via degradation of HOXA10

Endometriosis (ENDO) is a common gynecological disease that causes infertility in many women. Previous studies noted that the dysregulation of Homeo box A10 (HOXA10) in the endometrium of women with ENDO was involved in the failure of embryo implantation. However, the mechanism by which HOXA10 expression is reduced in women with ENDO is still poorly understood. Here we found that a member of the calcium (Ca²⁺)-dependent cysteine protease family calpain7 (CAPN7), negatively correlated with HOXA10, was highly expressed in the endometrium of infertile women with ENDO and was significantly downregulated during the window of embryo implantation in mice. Overexpression of CAPN7 in Ishikawa cells or in the uterus of mice inhibited embryo implantation in vitro and in vivo. In the current study, we identified a sequence rich in proline, glutamic acid, serine, and threonine (PEST sequence) that enhanced the Ca²⁺-dependent degradation of HOXA10 by CAPN7. Furthermore, the interaction between HOXA10 and CAPN7 repressed the transcriptional activity and protein stability of HOXA10. In contrast, the administration of the calpain inhibitor ALLN reversed the CAPN7-induced HOXA10 degradation. Moreover, truncation of the PEST motif in HOXA10 abolished its CAPN7-dependent proteolysis. These studies reveal a novel pattern of HOXA10 regulation via PEST sequence-mediated calpain proteolysis that was demonstrated to be reversed by a calpain inhibitor. Thus, the inhibition of CAPN7-induced HOXA10 degradation may represent a novel potential therapeutic method to improve impaired embryo implantation in women with ENDO.