Aberrant activation of signal transducer and activator of transcription-3 (STAT3) signaling in endometriosis

Mass spectrum oriented metabolomics for evaluating the efficacy and discovering the mechanism of Shaofuzhuyu Decoction for endometriosis of cold coagulation and blood stasis

Shaofuzhuyu Decoction (SFZYD) is a classical formula for treating endometriosis of cold coagulation and blood stasis (ECB). The clinical efficacy is definite, but the potential mechanisms require further exploration. The study aimed to reveal the metabolic mechanisms of SFZYD for treating ECB using mass spectrum oriented metabolomics. Firstly, the study has used metabolomics data to identify biomarkers and to investigate metabolic pathways. Then, the targets of SFZYD for treating ECB were dug by building and analyzing a biological network of biomarkers. Finally, the obtained targets were validated by molecular docking. This study found that SFZYD could significantly improve the biochemical indicators and metabolic abnormalities of ECB. A total of 18 ECB-related biomarkers in 7 pathways were identified. SFZYD was able to regulate the levels of 14 biomarkers that were involved in 5 metabolic pathways. Furthermore, the study yielded 119 SFZYD active ingredients, 1119 target proteins associated with endometriosis, 610 targets associated with biomarkers, 727 GO functions, and 159 KEGG pathways. Biological network analysis constructed a network diagram of herbs-ingredients-targets-biomarkers, and found 6 key active ingredients and 9 core targets. Molecular docking showed high affinities between key ingredients and core targets. This study elucidated that SFZYD plays a role in treating ECB through multi-component, multi-target, and multi-pathway.

ARG1 Is a Potential Prognostic Marker in Metastatic Endometrial Cancer

Endometrial cancer (EC) is the most common gynecologic malignancy. While the majority of patients present with early-stage and low-grade EC and have an excellent prognosis, a subset has metastatic disease at presentation or develops distant recurrence after initial treatment of the primary. However, the lack of prognostic biomarkers for metastatic EC is a critical barrier. Arginase 1 (ARG1) regulates the last step of the urea cycle, and an increase in ARG1 has been correlated as a poor prognostic factor in a variety of cancers. In the present study, ARG1 expression was evaluated as a potential prognostic marker for metastatic EC in endometrial hyperplasia and cancer of mice with Pten mutation as well as Pten and Mig-6 double mutations. While Pten mutation in the uterus is not sufficient for distant metastasis, mice with concurrent ablation of Mig-6 and Pten develop distant metastasis. Our immunostaining and RT-qPCR analysis revealed that the expression of ARG1 in early stage of EC as well as endometrial hyperplasia from mice deficient in Mig-6 and Pten mutations significantly increased compared to Pten mutation in the uterus. The results suggest that a high level of ARG1 is associated with poor prognosis in association with EC of mouse.

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.

Endometrial responsiveness to interferon-tau and its association with subsequent reproductive performance in dairy heifers

Our objectives were to evaluate the endometrial responsiveness of dairy heifers to an intrauterine infusion of recombinant bovine interferon-tau (rbIFN-τ) and to associate endometrial responses to rbIFN-τ with subsequent reproductive performance. In Experiments 1 and 2, cyclic heifers were enrolled in a 5-d CIDR Cosynch program for estrous synchronization, and blood sampling and ultrasonography examinations were performed on d 0, 4, 7, 11, and 14 of the estrous cycle. In Experiment 1, heifers were randomly assigned to receive an intrauterine infusion containing 2 µg of rbIFN-τ (rbIFN-τ = 19) or saline (CTRL = 19) into the uterine horn ipsilateral to the corpus luteum (CL) on d 14 of the estrous cycle. Six hours after the infusion, the infused uterine horn was flushed for sampling of the uterine luminal fluid (ULF) for analyses of composition, and the endometrium was biopsied for transcriptomics. In Experiment 2, 100 heifers received an intrauterine infusion of rbIFN-τ, and the same procedures for uterine sample collection described in Experiment 1 were performed. After the intrauterine test, heifers were enrolled in a breeding program and classified as highly fertile (HF; pregnant at first AI) or subfertile (SF; not pregnant at first AI). Statistical analyses were performed using linear regression models, which included the effects of treatment (Experiment 1: CTRL vs. rbIFN-τ) or fertility group (Experiment 2: HF vs. SF) and block of samples. Intrauterine infusion of rbIFN-τ increased the expression of classical interferon-stimulated genes in the endometrium (e.g., ISG15, MX1, OAS2, IRF9, and USP18), and an antiviral response was predicted to be the main downstream effect of the transcriptome changes. In addition, rbIFN-τ increased the abundance of cholesterol, glycerol, and the overall concentration of oxylipins in the ULF. Analysis of endometrial transcriptome between HF and SF heifers revealed important differences in the expression of proteins associated with cell signaling, metabolism, attachment, and migration, with a large representation of genes encoding extracellular matrix proteins. In general, differently expressed genes were expected to be downregulated by IFN-τ but seemed to fail to be downregulated in SF heifers, resulting in higher expression in SF compared with HF heifers. Subfertile heifers had lower concentrations of glycerol and an altered profile of oxylipins in the ULF, with lower abundance of oxylipins derived from arachidonic acid and dihomo-γ-linolenic acid, and greater abundance of oxylipins derived from linoleic acid. Measurements of ovarian function did not differ between groups and, therefore, did not influence the observed results in uterine biology. In conclusion, the endometrial responsiveness to IFN-τ is variable among individuals and associated with subsequent fertility of heifers, indicating that communication between conceptus and endometrium is critical for the uterine receptivity and survival of pregnancy.

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.

The involvement of RNA N6-methyladenosine and histone methylation modification in decidualization and endometriosis-associated infertility

Defective decidualization of endometrial stromal cells (ESCs) in endometriosis (EM) patients leads to inadequate endometrial receptivity and EM-associated infertility. Hypoxia is an inevitable pathological process of EM and participates in deficient decidualization of the eutopic secretory endometrium. Enhancer of zeste homology 2 (EZH2) is a methyltransferase which catalyses H3K27Me3, leading to decreased expression levels of target genes. Although EZH2 expression is low under normal decidualization, it is abundantly increased in the eutopic secretory endometrium of EM and is induced by hypoxia. Chromatin immunoprecipitation-PCR results revealed that decidua marker IGFBP1 is a direct target of EZH2, partially explaining the increased levels of histone methylation modification in defected decidualization of EM. To mechanism controlling this, we examined the effects of hypoxia on EZH2 and decidualization. EZH2 mRNA showed decreased m6 A modification and increased expression levels under hypoxia and decidualization combined treatment. Increased EZH2 expression was due to the increased expression of m6 A demethylase ALKBH5 and decreased expression of the m6 A reader protein YTHDF2. YTHDF2 directly bind to the m6 A modification site of EZH2 to promote EZH2 mRNA degradation in ESCs. Moreover, selective Ezh2 depletion in mouse ESCs increased endometrial receptivity and improved mouse fertility by up-regulating decidua marker IGFBP1 expression. This is the first report showing that YTHDF2 can act as a m6 A reader to promote decidualization by decreasing the stability of EZH2 mRNA and further increasing the expression of IGFBP1 in ESCs. Taken together, our findings highlight the critical role of EZH2/H3K27Me3 in decidualization and reveal a novel epigenetic mechanism by which hypoxia can suppress EM decidualization by decreasing the m6 A modification of EZH2 mRNA.

Association of endometriosis with Sjögren's syndrome: Genetic insights (Review)

Patients with a history of endometriosis have an increased risk of developing various autoimmune diseases such as rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, multiple sclerosis and celiac disease. There is a potential association between endometriosis and an increased susceptibility for Sjögren's syndrome (SS). SS is a common chronic, inflammatory, systemic, autoimmune, multifactorial disease of complex pathology, with genetic, epigenetic and environmental factors contributing to the development of this condition. It occurs in 0.5‑1% of the population, is characterized by the presence of ocular dryness, lymphocytic infiltrations and contributes to neurological, gastrointestinal, vascular and dermatological manifestations. Endometriosis is an inflammatory, estrogen‑dependent, multifactorial, heterogeneous gynecological disease, affecting ≤10% of reproductive‑age women. It is characterized by the occurrence of endometrial tissue outside the uterine cavity, mainly in the pelvic cavity, and is associated with pelvic pain, dysmenorrhea, deep dyspareunia and either subfertility or infertility. It is still unclear whether SS appears as a secondary response to endometriosis, or it is developed due to any potential shared mechanisms of these conditions. The aim of the present review was to explore further the biological basis only of the co‑occurrence of these disorders but not their association at clinical basis, focusing on the analysis of the partially shared genetic background between endometriosis and SS, and the clarification of the possible similarities in the underlying pathogenetic mechanisms and the relevant molecular pathways.

Paradoxical role of phosphorylated STAT3 in normal fertility and the pathogenesis of adenomyosis and endometriosis†

Signal transducer and activator of transcription 3 (STAT3), when phosphorylated at tyrosine 705, plays an important role in endometrial stromal cell decidualization and the receptivity of the endometrial epithelium during embryo implantation. However, the function of phosphorylated STAT3 (p-STAT3) in normal uterine receptivity is distinct from that in adenomyosis and endometriosis. In normal pregnancy, STAT3 phosphorylation in the endometrial epithelium determines the success of embryo implantation by regulating uterine receptivity. Additionally, p-STAT3 promotes cellular proliferation and differentiation during endometrial decidualization, which is crucial for embryonic development. In contrast, excessive STAT3 phosphorylation occurs in adenomyosis and endometriosis, which may lead to disease progression. Therefore, achieving a delicate balance in STAT3 activation is crucial. This review aimed to focus on the current understanding and knowledge gaps regarding the control of p-STAT3 activity in normal and pathological endometrial processes. This topic is important because precise control of p-STAT3 production could alleviate the symptoms of adenomyosis and endometriosis, improve endometrial receptivity, and potentially mitigate infertility without compromising normal fertility processes.

Identification of potential diagnostic biomarkers and therapeutic targets for endometriosis based on bioinformatics and machine learning analysis

PURPOSE

Endometriosis (EMs) is a major gynecological condition in women. Due to the absence of definitive symptoms, its early detection is very challenging; thus, it is crucial to find biomarkers to ease its diagnosis and therapy. Here, we aimed to identify potential diagnostic and therapeutic targets for EMs by constructing a regulatory network and using machine learning approaches.

METHODS

Three Gene Expression Omnibus (GEO) datasets were merged, and differentially expressed genes (DEGS) were identified after preprocessing steps. Using the DEGs, a transcription factor (TF)-mRNA-miRNA regulatory network was constructed, and hub genes were detected based on four different algorithms in CytoHubba. The hub genes were used to build a GaussianNB diagnostic model and also in docking analysis that were performed using Discovery Studio and AutoDock Vina software.

RESULTS

A total of 119 DEGs were identified between EMs and non-EMs samples. A regulatory network consisting of 52 mRNAs, 249 miRNAs, and 37 TFs was then constructed. The diagnostic model was introduced using the hub genes selected from the network (GATA6, HMOX1, HS3ST1, NFASC, and PTGIS) that its area under the curve (AUC) was 0.98 and 0.92 in the training and validation cohorts, respectively. Based on docking analysis, two chemical compounds, rofecoxib and retinoic acid, had potential therapeutic effects on EMs.

CONCLUSION

In conclusion, this study identified potential diagnostic and therapeutic targets for EMs which demand more experimental confirmations.

Synergy between Th1 and Th2 responses during endometriosis: A review of current understanding

Endometriosis is widely perceived as an estrogen-dependent chronic disorder with infertility and pelvic pain. Although the etiology of endometriosis has remained elusive, many studies have proclaimed the relevance of immune system disorders with endometriosis. With the discovery that the dysregulation of multiple biological functions in endometriosis is caused by the aberrant differentiation of T helper cells, a shift towards Th2 immune response may account for the disease progression. This review attempts to present mechanisms of cytokines, chemokines, signal pathways, transcription factors and some other factors related with the derivation of Th1/Th2 immune response involved in the development of endometriosis. The current understanding of treatment approaches and potential therapeutic targets will also be outlined with brief discussion.

Formononetin Inhibits Progression of Endometriosis via Regulation of p27, pSTAT3, and Progesterone Receptor: In Vitro and In Vivo Studies

OBJECTIVES

Formononetin is one of the phytoestrogens that functions like a selective estrogen receptor modulator (SERM). In this study, we evaluated the effects of formononetin on endometriosis progression in vitro and in vivo.

MATERIALS AND METHODS

After pathological confirmation, 10 eutopic and ectopic endometria were collected from patients with endometriosis. Ten eutopic endometria samples were collected from patients who did not have endometriosis. To determine the cytotoxic dose and therapeutic dose of formononetin, the concentration of 70% of the cells that survived after formononetin administration was estimated using a Cell counting kit-8 (CCK 8) assay. Western blot analysis was used to determine the relative expression levels of BAX, p53, pAKT, ERK, pERK, p27, and pSTAT3 in the eutopic endometria without endometriosis, eutopic endometria with endometriosis, and ectopic endometria with endometriosis as the formononetin concentration was increased. We confirmed the effect of formononetin on apoptosis and migration in endometriosis using fluorescence-activated cell sorting (FACS) and wound healing assays, respectively. A mouse model of endometriosis was prepared using a non-surgical method, as previously described. The mice were intraperitoneally administered formononetin for four weeks after dividing them into control, low-dose formononetin (40 mg/kg/day) treatment, and high-dose (80 mg/kg/day) formononetin treatment groups. All the mice were euthanized after formononetin treatment. Endometriotic lesions were retrieved and confirmed using hematoxylin and eosin (H&E) staining. Immunohistochemical (IHC) staining of p27 was performed.

RESULTS

We set the maximum concentration of formononetin administration to 80 μM through the CCK8 assay. Based on formononetin concentration, the expression levels of BAX, p53, pAKT, ERK, pERK, p27, and pSTAT3 proteins were measured using Western blot analysis (N = 4 per group). The expression level of pERK, p27, and pSTAT3 in eutopic endometrium with endometriosis tended to decrease with increasing formononetin concentration, and a significant decrease was noted at 80 μM. The expression of p27 in ectopic endometrium with endometriosis was also significantly decreased at 80 μM of formononetin. FACS analysis revealed that formononetin did not significantly affect apoptosis. In the wound healing assay, formononetin treatment revealed a more significant decrease in the proliferation of the eutopic endometrium in patients with endometriosis than in the eutopic endometrium without endometriosis. Relative expression of sex hormone receptors decreased with increasing formononetin doses. Although no significant differences were observed in the ER, PR-A, ERβ/ERα, and PR-B/PR-A, significant down-regulation of PR-B expression was noted after formononetin treatment at 80 μM. In the in vivo study, endometriotic lesions in the formononetin-treated group significantly decreased compared to those in the control group. The relative expression of p27 using IHC was highest in the control group and lowest in the high-dose formononetin treatment group.

CONCLUSIONS

Formononetin treatment was shown to inhibit the proliferation of eutopic and ectopic endometria in patients with endometriosis through the regulation of p27, pSTAT3, and PR-B. In an endometriosis mouse model, formononetin treatment significantly reduced the number of endometriotic lesions with decreased p27 expression. The results of this study suggest that formononetin may be used as a non-hormonal treatment option for endometriosis.

Progesterone Resistance in Endometriosis: Current Evidence and Putative Mechanisms

Endometriosis is an estrogen-dependent disease characterized by the growth of endometrial-like tissue outside the uterus. Progestins are currently the most commonly used treatment for endometriosis because of their excellent therapeutic effects and limited side effects. However, progestins have been unsuccessful in some symptomatic patients. The inability of the endometrium to respond properly to progesterone is known as progesterone resistance. An increasing body of evidence suggests the loss of progesterone signaling and the existence of progesterone resistance in endometriosis. The mechanisms of progesterone resistance have received considerable scholarly attention in recent years. Abnormal PGR signaling, chronic inflammation, aberrant gene expression, epigenetic alterations, and environmental toxins are considered potential molecular causes of progesterone resistance in endometriosis. The general objective of this review was to summarize the evidence and mechanisms of progesterone resistance. A deeper understanding of how these mechanisms contribute to progesterone resistance may help develop a novel therapeutic regimen for women with endometriosis by reversing progesterone resistance.

Network Pharmacology Was Used to Predict the Active Components and Prospective Targets of Paeoniae Radix Alba for Treatment in Endometriosis

Endometriosis is one of the most common benign gynecologic diseases. Paeoniae Radix Alba (PRA) has been utilized to treat endometriosis. We wished to identify potential targets for PRA in the treatment of endometriosis, as well as to provide a groundwork for future studies into its pharmacological mechanism of action. Network pharmacology was employed to conduct investigations on PRA. Target proteins were chosen from the components of PRA for endometriosis treatment. A protein-protein interaction (PPI) was established using overlapping genes. Analyses of enrichment of function and signaling pathways were undertaken using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes databases to select "hub genes." Finally, the feasibility of analysis based on network pharmacology was determined using real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting. We demonstrated that PRA has 25 bioactive components and 167 putative targets that are therapeutically important. The anti-inflammatory and immune-boosting actions of tumor necrosis factor, albumin, signal transducer and activator of transcription (STAT)3, mitogen-activated protein kinase, Jun, interleukin (IL)-1B, prostaglandin-endoperoxide synthase 2, matrix metalloproteinase-9, vascular endothelial growth factor A, and IL-6 were identified as prospective targets. Seven major compounds in PRA and related to the STAT3 pathway could bind spontaneously to it. RT-qPCR and western blotting showed that expression of STAT3 and phospho-STAT3 was reduced significantly after PRA intervention. Hence, analyses of the active components of traditional Chinese medicine formulations through network pharmacology may open up new ideas for the treatment of diseases.

Effects of STAT Inhibitors in Mouse Models of Endometriosis

The signal transducer and activator of transcription (STAT) pathway, which regulates cell proliferation and immunity, has been implicated in chronic inflammatory diseases such as rheumatoid arthritis. However, few reports have described the effects of STAT inhibitors on endometriosis, another chronic inflammatory disease. Here, we investigated the intraperitoneal microenvironment and the effects of a STAT inhibitor in a mouse model of endometriosis. In the treatment group, a STAT3 inhibitor (Stattic®, 80 mg/kg) was orally administered three times per week; control animals received orally dosed phosphate-buffered saline. Endometriosis-like lesions and peritoneal lavage fluid were collected before and 1, 2, and 3 weeks after STAT3 inhibitor administration was initiated. The lesion area was significantly increased in both groups after the first week. However, in the treatment group, the lesion areas were significantly reduced at weeks 2 and 3 compared with week 1. Transforming growth factor (TGF)-β messenger RNA (mRNA) levels in ascites cells were significantly lower at weeks 1 and 2 than at week 0. Interleukin (IL)-6 mRNA levels were significantly higher at week 1 than at week 0 but were significantly lower at weeks 2 and 3 than at week 1. Thus, STAT inhibitors appeared to reduce the extent of endometriosis in this mouse model, and may also inhibit the IL-6 signaling pathway and reduce TGF-β levels. This study suggests that STAT inhibitors warrant further exploration for use in the treatment of 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.

Interferon Signaling in the Endometrium and in Endometriosis

Endometriosis is an estrogen-dependent inflammatory disease that develops in reproductive-aged women who experience pelvic pain and infertility. Even though endometriosis is not a new disease, its molecular etiology has not been clearly elucidated. Defects in the immune system might be one of the factors that promote endometriosis progression. For example, elevated levels of proinflammatory cytokines are associated with endometriosis. Interferon is one of the cytokines that is elevated in endometriotic tissues compared with normal endometrium. Therefore, high interferon levels play a crucial role in endometriosis progression. In addition to endometriosis, however, interferon has a critical role in endometrial function, particularly in the initiation and maintenance of pregnancy. Therefore, this review describes the double-edged sword of interferon signaling in normal endometrial function versus endometriosis progression and also discusses interferon targeting as a new nonhormonal therapy for endometriosis. This approach may increase the efficacy of endometriosis treatment and reduce the adverse effects associated with current hormonal therapy for this disease.

Roles of microRNAs in Regulating Apoptosis in the Pathogenesis of Endometriosis

Endometriosis is a gynecologic disorder characterized by the presence of endometrial tissues outside the uterine cavity affecting reproductive-aged women. Previous studies have shown that microRNAs and their target mRNAs are expressed differently in endometriosis, suggesting that this molecule may play a role in the development and persistence of endometriotic lesions. microRNA (miRNA), a small non-coding RNA fragment, regulates cellular functions such as cell proliferation, differentiation, and apoptosis by the post-transcriptional modulation of gene expression. In this review, we focused on the dysregulated miRNAs in women with endometriosis and their roles in the regulation of apoptosis. The dysregulated miRNAs and their target genes in this pathophysiology were highlighted. Circulating miRNAs as potential biomarkers for the diagnosis of endometriosis have also been identified. As shown by various studies, miRNAs were reported to be a potent regulator of gene expression in endometriosis; thus, identifying the dysregulated miRNAs and their target genes could help discover new therapeutic targets for treating this disease. The goal of this review is to draw attention to the functions that miRNAs play in the pathophysiology of endometriosis, particularly those that govern cell death.

SIRT1 plays an important role in implantation and decidualization during mouse early pregnancy

Sirtuin 1 (SIRT1) is a member of the sirtuin family that functions to deacetylate both histones and non-histone proteins. Previous studies have identified significant SIRT1 upregulation in eutopic endometrium from infertile women with endometriosis. However, SIRT1 function in the uterus has not been directly studied. Using immunochemistry analysis, we found SIRT1 to be most strongly expressed at GD4.5 and GD5.5 in decidualized cells and at GD7.5 in secondary decidual cells in mouse. To assess the role of SIRT1 in uterine function, we generated uterine Sirt1 conditional knockout mice (Pgrcre/+Sirt1f/f; Sirt1d/d). A 6-month fertility trial revealed that Sirt1d/d females were subfertile. Implantation site numbers were significantly decreased in Sirt1d/d mice compared with controls at GD5.5. Sirt1d/d implantation sites at GD4.5 could be divided into two groups, Group #1 with luminal closure and nonspecific COX2 expression compared with controls (14/20) and Group #2 with an open lumen and no COX2 (6/20). In Sirt1d/d Group #1, nuclear FOXO1 expression in luminal epithelial cells was significantly decreased. In Sirt1d/d Group #2, nuclear FOXO1 expression was almost completely absent, and there was strong PGR expression in epithelial cells. At GD5.5, stromal PGR and COX2 were significantly decreased in Sirt1d/d uterine in the areas surrounding the embryo compared with controls, indicating defective decidualization. An artificially induced decidualization test revealed that Sirt1d/d females showed defects in decidualization response. All together, these data suggest that SIRT1 is important for decidualization and contributes to preparing a receptive endometrium for successful implantation.

Evaluation of endometrial receptivity and implantation failure

PURPOSE OF REVIEW

To succinctly review the basic mechanisms of implantation and luteal phase endometrial differentiation, the etiologies of impaired endometrial function and receptivity, and the current methods that exist to evaluate and treat impaired endometrial receptivity.

RECENT FINDINGS

Human embryo implantation requires bidirectional communication between blastocyst and a receptive endometrium. Etiologies of impaired endometrial receptivity are varied. Some of these include delayed endometrial maturation, structural abnormalities, inflammation, and progesterone resistance. Current methods to evaluate endometrial receptivity include ultrasonography, hysteroscopy, and endometrial biopsy. Treatments are limited, but include operative hysteroscopy, treatment of endometriosis, and personalized timing of embryo transfer.

SUMMARY

Although some mechanisms of impaired endometrial receptivity are well understood, treatment options remain limited. Future efforts should be directed towards developing interventions targeted towards the known mediators of impaired endometrial receptivity.

BCL6, a key oncogene, in the placenta, pre-eclampsia and endometriosis

BACKGROUND

The key oncogene B-cell lymphoma 6 (BCL6) drives malignant progression by promoting proliferation, overriding DNA damage checkpoints and blocking cell terminal differentiation. However, its functions in the placenta and the endometrium remain to be defined.

OBJECTIVE AND RATIONALE

Recent studies provide evidence that BCL6 may play various roles in the human placenta and the endometrium. Deregulated BCL6 might be related to the pathogenesis of pre-eclampsia (PE) as well as endometriosis. In this narrative review, we aimed to summarize the current knowledge regarding the pathophysiological role of BCL6 in these two reproductive organs, discuss related molecular mechanisms, and underline associated research perspectives.

SEARCH METHODS

We conducted a comprehensive literature search using PubMed for human, animal and cellular studies published until October 2021 in the following areas: BCL6 in the placenta, in PE and in endometriosis, in combination with its functions in proliferation, fusion, migration, invasion, differentiation, stem/progenitor cell maintenance and lineage commitment.

OUTCOMES

The data demonstrate that BCL6 is important in cell proliferation, survival, differentiation, migration and invasion of trophoblastic cells. BCL6 may have critical roles in stem/progenitor cell survival and differentiation in the placenta and the endometrium. BCL6 is aberrantly upregulated in pre-eclamptic placentas and endometriotic lesions through various mechanisms, including changes in gene transcription and mRNA translation as well as post-transcriptional/translational modifications. Importantly, increased endometrial BCL6 is considered to be a non-invasive diagnostic marker for endometriosis and a predictor for poor outcomes of IVF. These data highlight that BCL6 is crucial for placental development and endometrium homeostasis, and its upregulation is associated with the pathogenesis of PE, endometriosis and infertility.

WIDER IMPLICATIONS

The lesson learned from studies of the key oncogene BCL6 reinforces the notion that numerous signaling pathways and regulators are shared by tumors and reproductive organs. Their alteration may promote the progression of malignancies as well as the development of gestational and reproductive disorders.

Non-Invasive and Mechanism-Based Molecular Assessment of Endometrial Receptivity During the Window of Implantation: Current Concepts and Future Prospective Testing Directions

Suboptimal endometrial receptivity and altered embryo-endometrial crosstalk account for approximately two-thirds of human implantation failures. Current tests of the window of implantation, such as endometrial thickness measurements and the endometrial receptivity assay, do not consistently improve clinical outcomes as measured by live birth rates. Understanding the mechanisms regulating the endometrial receptivity during the window of implantation is a critical step toward developing clinically meaningful tests. In this narrative review, the available literature is evaluated regarding mechanisms that regulate the endometrial receptivity during the window of implantation and the current tests developed. Overall, both animal and human studies point to five possible and interrelated mechanisms regulating the endometrial window of implantation: suitable synchrony between endometrial cells, adequate synchrony between the endometrium and the embryo, standard progesterone signaling and endometrial responses to progesterone, silent genetic variations, and typical morphological characteristics of the endometrial glands. The biological basis of current clinical markers or tests of window of implantation is poor. Future studies to elucidate the mechanisms shaping the window of implantation and to investigate the potential markers based on these mechanisms are required. In addition, molecular testing of the endometrium at single-cell resolution should be an initial step toward developing clinically meaningful tests for the optimal window of implantation. As understanding of the optimal window of implantation continues to evolve, one can envision the future development of non-invasive, mechanism-based testing of the window of implantation.

β-Klotho promotes glycolysis and glucose-stimulated insulin secretion via GP130

Impaired glucose-stimulated insulin secretion (GSIS) is a hallmark of type-2 diabetes. However, cellular signaling machineries that control GSIS remain incompletely understood. Here, we report that β-klotho (KLB), a single-pass transmembrane protein known as a co-receptor for fibroblast growth factor 21 (FGF21), fine tunes GSIS via modulation of glycolysis in pancreatic β-cells independent of the actions of FGF21. β-cell-specific deletion of Klb but not Fgf21 deletion causes defective GSIS and glucose intolerance in mice and defective GSIS in islets of type-2 diabetic mice is mitigated by adenovirus-mediated restoration of KLB. Mechanistically, KLB interacts with and stabilizes the cytokine receptor subunit GP130 by blockage of ubiquitin-dependent lysosomal degradation, thereby facilitating interleukin-6-evoked STAT3-HIF1α signaling, which in turn transactivates a cluster of glycolytic genes for adenosine triphosphate production and GSIS. The defective glycolysis and GSIS in Klb-deficient islets are rescued by adenovirus-mediated replenishment of STAT3 or HIF1α. Thus, KLB functions as a key cell-surface regulator of GSIS by coupling the GP130 receptor signaling to glucose catabolism in β-cells and represents a promising therapeutic target for diabetes.

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.

Warm and humidified insufflation gas during gynecologic laparoscopic surgery reduces postoperative pain in predisposed patients-a randomized, controlled multi-arm trial

BACKGROUND

Postoperative pain remains a common problem in gynecologic laparoscopy, especially in head zone-related regions, triggered by intra-abdominal pressure during capnoperitoneum. Humidified and prewarmed insufflation gas may ameliorate pain and be beneficial.

METHODS

This prospective randomized controlled parallel group multi-arm single-center study investigated the effects of temperature and humidity of insufflation gas on postoperative pain during gynecologic laparoscopy with a duration ≥ 60 min. Female participants (18-70 years) were blinded and randomly assigned-computer generated-to either insufflation with dry cold CO₂ with forced air warming blanket ("AIR"), humidified warm gas without forced air warming blanket ("HUMI"), or humidified warm gas with forced air warming blanket ("HUMI +"). We hypothesized that using humidified warm gas resulted in lower pain scores and less analgesic consumption. The primary endpoint postoperative pain was assessed for different pain localizations every 12 h during 7 days after surgery. Secondary endpoints were demand for painkillers and epidural anesthetics, length of stay in recovery room, and hospital stay. (Registration: ClinicalTrials.gov NCT02781194-completed).

RESULTS

150 participants were randomized. Compared to group "AIR" (n = 48), there was significantly less pain in group "HUMI +" (n = 48) in the recovery room (- 1.068; 95% CI - 2.08 to - 0.061), as well as significantly less ibuprofen use at day two (- 0.5871 g ± 0.258; p-value = 0.0471). Other variables did not change significantly. Stratification for presence of endometriosis or non-previous abdominal surgery in patient history revealed significantly less pain in both groups "HUMI" (n = 50) and "HUMI +" versus group "AIR." Related side effects were not noted.

CONCLUSION

In the overall population, the use of warm, humidified insufflation gas did not yield clinically relevant effects; however, in predisposed patients with endometriosis and who could otherwise expect high pain levels, warm and humidified gas may be beneficial.

Intranuclear Delivery of HIF-1α-TMD Alleviates EAE via Functional Conversion of TH17 Cells

T helper 17 (TH17) cells are involved in several autoimmune diseases such as multiple sclerosis (MS) and rheumatoid arthritis (RA). In addition to retinoic acid receptor-related orphan nuclear receptor gamma t (ROR-γt), hypoxia-inducible factor-1α (HIF-1α) is essential for the differentiation and inflammatory function of TH17 cells. To investigate the roles of HIF-1α in the functional regulation of TH17 cells under the normal physiological condition without genetic modification, the nucleus-transducible form of transcription modulation domain (TMD) of HIF-1α (ntHIF-1α-TMD) was generated by conjugating HIF-1α-TMD to Hph-1 protein transduction domain (PTD). ntHIF-1α-TMD was effectively delivered into the nucleus of T cells without cellular cytotoxicity. ntHIF-1α-TMD significantly blocked the differentiation of naïve T cells into TH17 cells in a dose-dependent manner via IL-17A and ROR-γt expression inhibition. However, T-cell activation events such as induction of CD69, CD25, and IL-2 and the differentiation potential of naïve T cells into TH1, TH2, or Treg cells were not affected by ntHIF-1α-TMD. Interestingly, TH17 cells differentiated from naïve T cells in the presence of ntHIF-1α-TMD showed a substantial level of suppressive activity toward the activated T cells, and the increase of Foxp3 and IL-10 expression was detected in these TH17 cells. When mRNA expression pattern was compared between TH17 cells and ntHIF-1α-TMD-treated TH17 cells, the expression of the genes involved in the differentiation and functions of TH17 cells was downregulated, and that of the genes necessary for immune-suppressive functions of Treg cells was upregulated. When the mice with experimental autoimmune encephalomyelitis (EAE) were treated with ntHIF-1α-TMD with anti-IL-17A mAb as a positive control, the therapeutic efficacy of ntHIF-1α-TMD in vivo was comparable with that of anti-IL-17A mAb, and ntHIF-1α-TMD-mediated therapeutic effect was contributed by the functional conversion of TH17 cells into immune-suppressive T cells. The results in this study demonstrate that ntHIF-1α-TMD can be a new therapeutic reagent for the treatment of various autoimmune diseases in which TH17 cells are dominant and pathogenic T cells.

G-CSF and IL-6 may be involved in formation of endometriosis lesions by increasing the expression of angiogenic factors in neutrophils

Evidence accumulated in recent years has revealed that neutrophils are involved in the initial establishment of endometriosis, which is well-known as a chronic inflammatory disease. So far, why and how neutrophils promote the formation of early endometriosis are still unclear. In this study, using a mouse model of endometriosis, we demonstrated that endometriosis mice (EMs mice) had a significantly increased number of neutrophils in peritoneal fluids and lesions, and increased levels of granulocyte colony-stimulating factor (G-CSF) and IL-6 in serum and peritoneal fluids compared to the control group. In the neutrophils and uterine fragments co-injection experiment, neutrophils regulated by G-CSF and IL-6 had a similar effect to neutrophils from EMs mice, increasing the number, area, weight and microvessel density (MVD) of endometriotic lesions. Blocking the effect of G-CSF and IL-6 in EMs mice resulted in a decrease in the number, area and weight of endometriotic lesions. Following the depletion of neutrophils in vivo using a anti-Ly6G antibody, the MVD in the lesions of mice treated with neutrophils from EMs mice and neutrophils from pG/pI6 mice were significantly reduced. Neutrophils from EMs mice and neutrophils from pG/pI6 mice altered the expression levels of Mmp9, Bv8 and Trail genes compared to the neutrophils from PBS-treated mice. IL-6 together with G-CSF induced a higher expression of phospho-STAT3 and STAT3 in neutrophils. These findings suggest that neutrophils modulated by G-CSF and IL-6 through the STAT3 pathway alter the expression levels of the angiogenesis-related genes Mmp9, Bv8 and Trail, and may promote the establishment of early endometriosis.

Identification of Key Differentially Methylated/Expressed Genes and Pathways for Ovarian Endometriosis by Bioinformatics Analysis

The goal of this study was to identify genes that were differentially methylated and differentially expressed and their related signaling pathways in ovarian endometriosis tissue. First, the DNA methylation and gene expression profiles in the endometrial tissue of patients with ovarian endometriosis were studied using Illumina 450K methylation microarray analysis and the GSE141549 gene expression dataset. Second, differentially methylated and differentially expressed genes, herein referred to as differentially methylated/expressed genes, were identified and protein-protein interaction networks and functional analysis of these genes were determined. Third, qPCR and immunohistochemistry of patient samples was used to confirm the differential expression of a subset of differentially methylated/expressed genes. Finally, the GSE7305 dataset was used confirm the expression profile of differentially methylated/expressed genes and to determine the potential usefulness of these genes for diagnosis of endometriosis. A total of 37 hypermethylated low-expression genes and 66 hypomethylated high-expression genes were identified in ovarian endometriosis patients. Protein-protein interaction and functional analysis highlighted 8 hypermethylated low-expression genes (KRT19, KRT8, ESR1, PRL, SFN, IL20RA, IL2RB, and PAX8) and 4 hypomethylated high-expression genes (CYP11A1, NR5A1, ME1, and GSTM1). Significantly, both of these gene sets had a diagnostic value for patients with ovarian endometriosis. Signaling pathways that were identified included JAK-STAT (involving IL20RA and IL2RB), prolactin (involving PRL and ESR1), Staphylococcus aureus infection (involving KRT19), viral protein interaction with cytokine and cytokine receptor (involving IL20RA and IL2RB), cytokine-cytokine receptor interaction (involving IL20RA and IL2RB), and drug metabolism-cytochrome P450 (involving GSTM1). The differentially methylated/expressed genes and enriched signaling pathways identified in this study are likely to be associated with the process of ovarian endometriosis.

Evaluation of BCL6 and SIRT1 as Non-Invasive Diagnostic Markers of Endometriosis

(1) Background: Endometriosis is characterized by the presence of endometrial glands and stroma outside of the uterus and is often associated with severe pelvic pain and infertility. Our study explored the utilization of B-Cell Lymphoma 6 (BCL6) and Sirtuin 1 (SIRT1) as potential biomarkers in serum, plasma, urine, and cervical mucus for a non-invasive diagnostic test for endometriosis. BCL6 was chosen based on its previously reported elevated expression in endometrial biopsies, and SIRT1 is co-expressed and upregulated in the endometrium of women with endometriosis. (2) Methods: BCL6 and SIRT1 levels were measured using enzyme-linked immunoassay (ELISA) in samples from 20 women with endometriosis (ten with stages I/II and ten with stages III/IV) and ten women without endometriosis. (3) Results: Levels of SIRT1 in sera showed a statistically significant elevation in advanced stages III/IV compared to controls and stages I/II. No significant differences were found in other bodily fluids for SIRT1 or any bodily fluids tested for BCL6. (4) Conclusions: These results suggest some potential of SIRT1 expression within serum as a predictor of advanced asymptomatic stages of endometriosis. Using immunohistochemistry (IHC) staining and H-SCORE values for the elevated BCL6 (and potentially SIRT1) levels in endometrial biopsy samples seems to have higher diagnostic potential based on the previously published studies.

Recombinant human IL-37 inhibited endometriosis development in a mouse model through increasing Th1/Th2 ratio by inducing the maturation of dendritic cells

BACKGROUND

Endometriosis is a serious reproductive and general health consequences. Recombinant human IL-37 (rhIL-37) is an inhibitor of inflammation.

METHODS

ELISA assay was performed to detect the concentration of cytokines. Flow cytometry was used to analyze cell proportion. Besides, qRT-PCR and western blotting assay were used to detect the level of gene and protein, respectively. Transwell co-culture system was used for the co-culture of dendritic cells (DCs) and CD4⁺T cells.

RESULTS

Our data showed that rhIL-37 inhibited the development of ectopic lesions in the mice with endometriosis, increased Th1/Th2 ratio and induced DCs maturation. The co-culture system of DCs and CD4⁺T cells demonstrated that rhIL-37 increased Th1/Th2 cell ratio through promoting DCs maturation. Moreover, the expression of IL-4 in the DCs derived from healthy mice was inhibited by rhIL-37 treatment. rhIL-37 increased Th1/Th2 cell ratio through inhibiting IL-4 in DCs. Subsequently, our results proved that rhIL-37 promoted the maturation of DCs via inhibiting phosphorylation of STAT3. Activation of STAT3 could reverse rhIL-37-induced maturation of DCs.

CONCLUSION

Overall, rhIL-37 could protect against endometriosis through increasing the ratio of Th1/Th2 cells via inducing DCs maturation and inhibiting IL-4 expression in the DCs. Furthermore, rhIL-37 induced DCs maturation by inhibiting STAT3 phosphorylation. Our data confirmed the protective effect of rhIL-37 in endometriosis. These data may provide a novel idea for the treatment of the disease.

LncRNA AFAP1-AS1 regulates proliferation and apoptosis of endometriosis through activating STAT3/TGF-β/Smad signaling via miR-424-5p

AIM

Endometriosis is a common gynecological disorder characterized by chronic pelvic pain and infertility, which negatively affects women's health worldwide. AFAP1-AS1 has been implicated in endometriosis lesions recently, but its mechanism of endometriosis progression remains unclear.

METHODS

Endometrial stromal cells (ESCs) were used to identify the role of AFAP1-AS1 in endometriosis. The migratory capability was determined by transwell. Gene and protein expressions were identified by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. Cell viability and apoptosis were detected by MTT assays and flow cytometry, respectively. Luciferase report assays were used to identify the interaction of AFAP1-AS1, miR-424-5p and signal transducer and activator of transcription 3 (STAT3).

RESULTS

AFAP1-AS1 knockdown or miR-424-5p overexpression inhibited proliferation and migration, and promoted apoptosis in ESCs. In addition, knockdown of AFAP1-AS1 repressed the expression of ki-67 and Bcl-2, and promoted the levels of cleaved caspase-3 and Bax. Furthermore, knockdown of AFAP1-AS1 inhibited the conversion of E-cadherin to N-cadherin and the expression of Snail. Moreover, AFAP1-AS1 activated the STAT3/transforming growth factor-β1 (TGF-β1)/Smad2 axis via directly targeting miR-424-5p. The regulatory effect of AFAP1-AS1 silencing in ESC migration, proliferation, and apoptosis was reversed by miR-424-5p inhibition or STAT3 overexpression.

CONCLUSIONS

AFAP1-AS1 silencing could inhibit cell proliferation and promote apoptosis by regulating STAT3/TGF-β/Smad signaling pathway via targeting miR-424-5p in ESCs. AFAP1-AS1 may be a potential therapeutic target of controlling the progression of endometriosis.

PPARγ Agonists: Emergent Therapy in Endometriosis

Endometriosis is one of the major gynecological diseases of reproductive-age women. This disease is characterized by the presence of glands and stroma outside the uterine cavity. Several studies have shown the major role of inflammation, angiogenesis, adhesion and invasion, and apoptosis in endometriotic lesions. Nevertheless, the mechanisms underlying endometriotic mechanisms still remain unclear and therapies are not currently efficient. The introduction of new agents can be effective by improving the condition of patients. PPARγ ligands can directly modulate these pathways in endometriosis. However, data in humans remain low. Thus, the purpose of this review is to summarize the potential actions of PPARγ agonists in endometriosis by acting on inflammation, angiogenesis, invasion, adhesion, and apoptosis.

Efficacy of niclosamide on the intra-abdominal inflammatory environment in endometriosis

Endometriosis, a common gynecological disease, causes chronic pelvic pain and infertility in women of reproductive age. Due to the limited efficacy of current therapies, a critical need exists to develop new treatments for endometriosis. Inflammatory dysfunction, instigated by abnormal macrophage (MΦ) function, contributes to disease development and progression. However, the fundamental role of the heterogeneous population of peritoneal MΦ and their potential druggable functions is uncertain. Here we report that GATA6-expressing large peritoneal MΦ (LPM) were increased in the peritoneal cavity following lesion induction. This was associated with increased cytokine and chemokine secretion in the peritoneal fluid (PF), as well as MΦ infiltration, vascularization and innervation in endometriosis-like lesions (ELL). Niclosamide, an FDA-approved anti-helminthic drug, was effective in reducing LPM number, but not small peritoneal MΦ (SPM), in the PF. Niclosamide also inhibits aberrant inflammation in the PF, ELL, pelvic organs (uterus and vagina) and dorsal root ganglion (DRG), as well as MΦ infiltration, vascularization and innervation in the ELL. PF from ELL mice stimulated DRG outgrowth in vitro, whereas the PF from niclosamide-treated ELL mice lacked the strong stimulatory nerve growth response. These results suggest LPM induce aberrant inflammation in endometriosis promoting lesion progression and establishment of the inflammatory environment that sensitizes peripheral nociceptors in the lesions and other pelvic organs, leading to increased hyperalgesia. Our findings provide the rationale for targeting LPM and their functions with niclosamide and its efficacy in endometriosis as a new non-hormonal therapy to reduce aberrant inflammation which may ultimately diminish associated pain.

Tofacitinib alters STAT3 signaling and leads to endometriosis lesion regression

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

ARID1A and PGR proteins interact in the endometrium and reveal a positive correlation in endometriosis

Endometriosis is a disorder in which endometrial cells normally limited to the lining of the uterus proliferate outside the uterine cavity and can cause pelvic pain and infertility. ARID1A levels are significantly reduced in the eutopic endometrium from women with endometriosis. Uterine specific Arid1a knock-out mice were infertile due to loss of epithelial progesterone receptor (PGR) signaling. However, the functional association of ARID1A and PGR in endometriosis has not been studied. We examined the expression patterns and co-localization of ARID1A and PGR in eutopic endometrium from women with and without endometriosis using immunostaining and Western blot analysis. ARID1A and PGR proteins co-localized in the epithelium during the proliferative and the early secretory phases. Our immunoprecipitation analysis and proximity ligation assay (PLA) revealed physical interaction between ARID1A and PGR-A but not PGR-B in the mouse and human endometrium. ARID1A levels positively correlated with PGR levels in the eutopic endometrium of women with endometriosis. Our results bring new perspectives on the molecular mechanisms involved in endometrial receptivity and progesterone resistance in endometriosis. The interrelationship between ARID1A and PGR may contribute to explaining the non-receptive endometrium in endometriosis-related infertility.

Genetic and epigenetic changes in the eutopic endometrium of women with endometriosis: association with decreased endometrial αvβ3 integrin expression

About 40% of women with infertility and 70% of women with pelvic pain suffer from endometriosis. The pregnancy rate in women undergoing IVF with low endometrial integrin αvβ3 (LEI) expression is significantly lower compared to the women with high endometrial integrin αvβ3 (HEI). Mid-secretory eutopic endometrial biopsies were obtained from healthy controls (C; n=3), and women with HEI (n=4) and LEI (n=4) and endometriosis. Changes in gene expression were assessed using human gene arrays and DNA methylation data were derived using 385 K Two-Array Promoter Arrays. Transcriptional analysis revealed that LEI and C groups clustered separately with 396 differentially expressed genes (DEGs) (P<0.01: 275 up and 121 down) demonstrating that transcriptional and epigenetic changes are distinct in the LEI eutopic endometrium compared to the C and HEI group. In contrast, HEI vs C and HEI vs LEI comparisons only identified 83 and 45 DEGs, respectively. The methylation promoter array identified 1304 differentially methylated regions in the LEI vs C comparison. The overlap of gene and methylation array data identified 14 epigenetically dysregulated genes and quantitative RT-PCR analysis validated the transcriptomic findings. The analysis also revealed that aryl hydrocarbon receptor (AHR) was hypomethylated and significantly overexpressed in LEI samples compared to C. Further analysis validated that AHR transcript and protein expression are significantly (P<0.05) increased in LEI women compared to C. The increase in AHR, together with the altered methylation status of the 14 additional genes, may provide a diagnostic tool to identify the subset of women who have endometriosis-associated infertility.

SMURF1-mediated ubiquitylation of SHP-1 promotes cell proliferation and invasion of endometrial stromal cells in endometriosis

Background

Endometriosis is a widespread benign gynecological disorder. The signal transducer and activator of transcription 3 (STAT3) signaling pathway plays an important role in the pathogenesis of endometriosis through regulating proliferation and invasion of endometrial stromal cells. Furthermore, the protein tyrosine phosphatase (PTP), SH2 domain-containing phosphatase 1 (SHP-1), negatively regulates STAT3 activation. However, regulation of the SHP-1-STAT3 pathway in the pathogenesis of endometriosis remains unclear.

Methods

Cell proliferation and invasion were assessed by Cell Counting Kit-8 (CCK-8) assay and Transwell analysis, respectively, to investigate the role and regulation of the SHP-1-STAT3 pathway in the proliferation and invasion of endometrial stromal cells. Expression of Smad ubiquitin regulatory factor 1 (SMURF1), SHP-1, matrix metalloproteinase 2 (MMP2), MMP9, STAT3, and phospho-STAT3 (p-STAT3) level in patients with endometriosis were measured by Western blotting and/or immunohistochemical staining. The interaction between SMURF1 and SHP-1 was investigated by co-immunoprecipitation and ubiquitylation analysis.

Results

The present study demonstrated that downregulation of SHP-1 expression in patients with endometriosis was negatively correlated with SMURF1 expression. SMURF1, an E3 ubiquitin ligase, activated the STAT3 pathway via ubiquitylation and degradation of SHP-1. Furthermore, SMURF1 promoted cell proliferation and invasion of endometrial stromal cells by activating STAT3 signaling and expression of its downstream targets, MMP2 and MMP9, whereas SHP-1 demonstrated an inverse effect. Additionally, SHP-1 inhibited SMURF1-mediated cell invasion and proliferation of endometrial stromal cells.

Conclusions

Our findings indicate that SMURF1-mediated ubiquitylation of SHP-1 regulates endometrial stromal cell proliferation and invasion during endometriosis.

Endometrial causes of recurrent pregnancy losses: endometriosis, adenomyosis, and chronic endometritis

Chronic inflammatory processes affecting the endometrium, as encountered in endometriosis, adenomyosis, and chronic endometritis, alter endometrial receptivity. These disorders are associated with early pregnancy losses and possibly recurrent pregnancy losses (RPL). In the cases of endometriosis, other factors associated with the disease also are susceptible of causing miscarriages and possibly RPL, such as an impact of intrapelvic inflammatory processes affecting the oocyte and embryo in case of natural conception. Conversely these latter effects obviously are bypassed in case of assisted reproductive technology. Chronic inflammation of the endometrium in the condition known as chronic endometritis also causes early pregnancy losses and RPL with beneficial effects achieved when specific treatment is undertaken.

Integration of genome-wide association study and expression quantitative trait locus mapping for identification of endometriosis-associated genes

To determine whether genetic predisposition to endometriosis varies depending on ethnicity and in association with expression quantitative trait loci (eQTL) in a Taiwanese population. We conducted a genome-wide association study (GWAS) and replicated it in 259 individuals with laparoscopy-confirmed stage III or IV endometriosis (cases) and 171 women without endometriosis (controls). Their genomic DNA was extracted from blood and evaluated by the GWAS of Taiwan Biobank Array. Novel genetic variants that predispose individuals to endometriosis were identified using GWAS and replication, including rs10739199 (P = 6.75 × 10^-5) and rs2025392 (P = 8.01 × 10^-5) at chromosome 9, rs1998998 (P = 6.5 × 10^-6) at chromosome 14, and rs6576560 (P = 9.7 × 10^-6) at chromosome 15. After imputation, strong signals were exhibited by rs10822312 (P = 1.80 × 10^-7) at chromosome 10, rs58991632 (P = 1.92 × 10^-6) and rs2273422 (P = 2.42 × 10^-6) at chromosome 20, and rs12566078 (P = 2.5 × 10^-6) at chromosome 1. We used the Genotype-Tissue Expression (GTEx) database to observe eQTL. Among these SNPs, the cis-eQTL rs13126673 of inturned planar cell polarity protein (INTU) showed significant association with INTU expression (P = 5.1 × 10^-33). Moreover, the eQTL analysis was performed on endometriotic tissues from women with endometriosis. The expression of INTU in 78 endometriotic tissue of women with endometriosis is associated with rs13126673 genotype (P = 0.034). To our knowledge, this is the first GWAS to link endometriosis and eQTL in a Taiwanese population.

miR-202-3p overexpression attenuates endometriosis-like lesions by modulating YAP-dependent transcription of S100A6 in murine models

AIM

Recent evidence has suggested the important implications of microRNAs (miRNAs) in the processes of proliferation and tissue remodeling in endometriosis (EMS). We therefore aim to determine the role of miR-202-3p in the pathophysiology of EMS and its underlying mechanisms.

METHODS

Experimental endometriosis was induced in ovariectomized mice implanted with a slow-release 17-β estradiol capsule. Eutopic endometrial stromal cells (euESCs) were isolated and assayed for proliferative, invasive and apoptotic properties by EdU staining, Transwell assays, and flow cytometry. The invasive and apoptotic features in the endometrium of mice with EMS in vivo were evaluated by using immunohistochemical staining and TUNEL assays.

RESULTS

miR-202-3p was observed to be downregulated in the endometrial tissues of EMS patients. MiR-202-3p was also found to target YAP1 which resulted in reduced euESC proliferation and invasion and increased apoptosis. YAP1 was able to phosphorylated STAT3 which consequently upregulated S100A6 to promote the proliferative and invasive abilities of euESCs. MiR-202-3p was thereby proposed to act as an inhibitor of proliferation and tissue damage in the in vivo setting of EMS, its effects however, were able to be counteracted byS100A6, which reversed the effects of miR-202-3p on tissue injury and cell proliferation.

CONCLUSION

Our data together evidenced that miR-202-3p targeted YAP1 to reduce STAT3-mediated S100A6 whereby preventing the progression of EMS.

Effect of miR-194-5p regulating STAT1/mTOR signaling pathway on the biological characteristics of ectopic endometrial cells from mice

OBJECTIVE

This study aimed to find out the regulatory mechanism of miR-194-5p targeting STAT1/mTOR signaling pathway on the biological characteristics of endometrial epithelium cells from mice with endometriosis (EMs).

METHODS

Mouse model of EMs was constructed to observe the histopathological changes of endometrium via HE staining. The targeting relationship between miR-194-5p and STAT1 was verified by bioinformatics website as well as dual-luciferase reporter assay. The expressions of miR-194-5p and STAT1 in the cells were detected by qRT-PCR, then, the proliferative activity, invasion ability, apoptosis and cycle of cells were determined after overexpression of miR-194-5p, or down-regulation of miR-194-5p and STAT1.

RESULTS

In the ectopic endometrial epithelial cells, the expression of miR-194-5p was reduced, while the expression of STAT1 was significantly elevated. Overexpression of miR-194-5p or down-regulation of STAT1 significantly inhibited the proliferation and invasion and promoted apoptosis of ectopic endometrial cells. While down-regulation of miR-194-5p reversed the results, and inhibition of STAT1 partially reversed the effects partially.

CONCLUSIONS

The miR-194-5p inhibits mTOR signaling pathway by inhibiting the expression of STAT1 gene, so as to inhibit the proliferation and invasion, as well as to promote the apoptosis of ectopic endometrial epithelial cells in mice with EMs.

ENDOMETRIC FACTOR OF ENDOMETRIOSIS-ASSOCIATED INFERTILITY

BACKGROUND Despite numerous studies and a not decreasing amount of endometriosis and associated infertility, the study of endometriosis- associated infertility does not lose its relevance, and the characteristics of the endometrium is appeared to be central and predictive factors that determine the success of overcoming infertility. OBJECTIVE To reflect the molecular genetic features of the state of the endometrium with endometriosis associated with infertility, expand the understanding of its pathogenesis, substantiate theoretical aspects of the use of hormonal preimplantation preparation of the endometrium in endometriosis-associated infertility. MATERIALS AND METHODS To write this review, we searched for domestic and foreign publications in Russian and international search systems (eLIBRARY, PubMed, MedLine, Crossref, etc.) over the past 1–16 years. RESULTS The model of changes in endometrial receptivity is examined the mechanisms of resistance to progesterone and overproduction of estrogens as key endometrial factors in the pathogenesis of endometriosis-associated infertility and theoretical justification for the use of hormonal therapy for the preimplantation preparation of compromised endometrium is given. CONCLUSION Despite the large number of publications, there is no consensus and the same approaches to determining the receptivity of the endometrium and its role in implantation disorders in endometriosis, as well as clear ideas about the pathogenesis of endometriosis-associated infertility. A personalized approach in the management of patients with endometriosis-associated infertility will lead to a common denominator of many factors affecting reproduction and determine their potential role in both the diagnosis and treatment of a particular patient.

A novel role of the miR-152-3p/ERRFI1/STAT3 pathway modulates the apoptosis and inflammatory response after acute kidney injury

Acute kidney injury (AKI) is one of the most common and serious complications in the development of sepsis. Many microRNAs are closely related to the occurrence, development, and prognosis of sepsis AKI (but the effect and mechanism of miR-152-3p in it is unclear). Meanwhile, the ERBB receptor feedback inhibitor 1 (ERRFI1) has a negative regulatory effect on signal transducer and activator of transcription 3 (STAT3) phosphorylation on uterine epithelial cells. But, the relationship between miR-152-3p and renal function, inflammatory factors, prognosis in AKI, and the mechanism is not clear. Analyzing sepsis-induced AKI rats and the cell model, our results revealed that miR-152-3p was upregulated in septic AKI patients and positively correlated with serum creatinine, urea nitrogen, interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α). Downregulation of miR-152-3p with the inhibitor could dramatically attenuate caspase-3, bromodeoxyuridine and IL-1β, and TNF-α in the AKI rats' model. Furthermore, downregulation of miR-152-3p attenuated lipopolysaccharide-induced apoptosis and inflammatory response in HK-2 and HEK293 cells. To further explore the mechanisms, we found ERRFI1 was appreciably downregulated and STAT3 was upregulated in AKI, whereas ERRFI1 was radically upregulated and STAT3 was greatly downregulated after the addition of miR-152-3p inhibitor, no matter in vivo or in vitro. Summarily, our study confirmed that miR-152-3p could promote the expression of STAT3 by targeting ERRFI1, aggravate cell apoptosis and inflammatory response, and thereby aggravate kidney injury in sepsis AKI.

The flavonoid-enriched extract from the root of Smilax china L. inhibits inflammatory responses via the TLR-4-mediated signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Smilax china L. has been used clinically to treat various inflammatory disorders with a long history.

AIM OF THE STUDY

To investigate the mechanisms underlying anti-inflammatory action of the extract from the herb.

MATERIALS AND METHODS

The extract was identified and quantified using the Ultra Performance Liquid Chromatography-Photo Diode Array-Mass Spectrometer method. The anti-inflammatory activities were examined in xylene-induced mouse ear edema and cotton ball-induced rat granuloma. The inflammatory mediators, pro-inflammatory cytokines and TLR-4-mediated signals in LPS-stimulated RAW264.7 macrophages were determined using ELISA, real-time PCR, Western blot and/or immunofluorescence, respectively.

RESULTS

The extract was found to enrich flavonoids (44.3%, mainly astilbin, engeletin, isoastilbin, cinchonain Ia, quercetin-3-O-a-L-rhamnopyranoside and chlorogenic acid). The flavonoid-enriched extract (FEE) inhibited xylene-induced mouse ear edema and cotton ball-induced rat granuloma, and suppressed LPS-induced over-release and/or overexpression of tumor necrosis factor-α, cyclooxygenase-2, inducible nitric oxide synthase, interleukin-1β and interleukin-6 in RAW264.7 macrophages. Mechanistically, FEE suppressed protein overexpression of TLR-4 and its downstream signals, MyD88 protein, phosphorylated inhibitory κB-α, NF-κB-P65 and MAPK p38, as well as phosphorylation of phosphoinositide 3-kinase (PI3K) p85α at Tyr⁶⁰⁷ and Akt at Ser⁴⁷³ in LPS-stimulated macrophages. The mode of the anti-inflammatory action of FEE was similar to that of TAK-242 (a selective TLR-4 inhibitor).

CONCLUSIONS

The present results demonstrate that FEE inhibit inflammatory responses via the TLR-4-mediated signaling pathway. Our findings go a new insight into the mechanisms underlying anti-inflammatory action of the herb, and provide a better understanding of its use for inflammatory diseases.

microRNA-141 inhibits TGF-β1-induced epithelial-to-mesenchymal transition through inhibition of the TGF-β1/SMAD2 signalling pathway in endometriosis

PURPOSE

Recent studies have demonstrated the differential expression of micro(mi)RNAs in endometriosis. Previously, we reported the low expression of miR-141 in patients with this disease. Epithelial-to-mesenchymal transition (EMT) and the transforming growth factor-beta1 (TGF-β1)-induced SMAD2 signalling pathway are central to tumour proliferation and invasion. However, the role of miR-141 in regulating the TGF-β1/SMAD2 signalling pathway and the associated EMT to be elucidated.

METHODS

The levels of TGF-β1/SMAD2 signalling and EMT markers expression in eutopic and ectopic endometria of endometriosis were determined by immunohistochemistry and western blot analyses. MiR-141 expression was analysed by quantitative reverse-transcription polymerase chain reaction. Cellular invasion and proliferation were determined by transwell and CCK-8 assays, respectively. Functional assay of miR-141 was performed using plasmid and shRNA transfection methods.

RESULT

The presence of miR-141, EMT, and TGF-β1/SMAD2 signalling markers were detected in eutopic and ectopic endometria of endometriosis. TGF-β1-induced EMT in Ishikawa (ISK) cells by activating the SMAD2 signalling pathway, whereas miR-141 inhibited the TGF-β1-induced EMT, proliferation and invasion abilities of these cells.

CONCLUSION

These data identify miR-141 as a novel driver of EMT in endometriosis, implicates the link between miR-141 and TGF-β1/SMAD2 signalling pathway in the context of endometriosis, and underscore the role of EMT in the development of endometriosis.

MicroRNAs as Key Regulators of Ovarian Cancers

The tumor microenvironment can be realistically viewed as an active battle ground between the host immune system and the growing tumor cells. This reactive space surrounding the tumor possesses several possibilities and facilitates the progression of a tumor from a neoplastic stage to that of metastasis. The contemporary approach of understanding the cancer biology from a “within the cell” perspective has been largely challenged with complex and intricate “outside the cell” events. Thus understanding the biology of the tumor microenvironment has been of scientific and clinical interest. Small non-coding microRNAs with a pleotropic and wide range of cellular gene targets can be reasonably hypothesized to regulate the events of carcinogenesis and progression. MicroRNAs have been investigated in different cancer models, and evidence of their involvement in the regulation of the tumor microenvironment has been of much interest. In particular, a major interest has been exploring the role of the tumor microenvironment in regulating the interaction of cancer cells with surrounding stromal components and the effect of such interactions on the cancer cells. Fine-tuned regulation by these microRNAs extends our contemporary understanding of these small biomolecules in epigenetic regulations. This review focuses on microRNAs that are dysregulated in ovarian carcinomas, their effect on the components of the tumor microenvironment, and the correlation of their heterogeneous expression profiles with disease severity and prognosis in patients. In addition, this paper also discusses the differential expression of exosomal microRNAs that are known to link the cancer cell with its microenvironment, facilitating the development of an improved prognostic/diagnostic marker and effective therapeutic regime.

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.

What exactly is endometrial receptivity?

Endometrial receptivity is a complex process that provides the embryo with the opportunity to attach, invade, and develop, culminating in a new individual and continuation of the species. The window of implantation extends 3-6 days within the secretory phase in most normal women. In certain inflammatory or anatomic conditions, this window is narrowed or shifted to preclude normal implantation, leading to infertility or pregnancy loss. Of the factors that prevent normal implantation and pregnancy, embryo and endometrial quality share responsibility. In this review, we highlight the advances in the study of implantation from the perspective of the endometrium, normally a barrier to implantation. New advances will allow the early identification of defects in endometrial receptivity and provide new avenues for treatment that promote successful establishment of pregnancy.

miR-451a Inhibition Reduces Established Endometriosis Lesions in Mice

Endometriosis is an estrogen-dependent pro-inflammatory disease that affects 6% to 10% of reproductive-age women. Current treatments target sex steroids, and none are disease-specific. MicroRNA treatments have provided promising results for some chronic diseases and cancers. We have previously shown microRNA 451a is increased in endometriosis and that elevation of 451a contributes to the pathophysiology of the disease. Here, we propose inhibition of miR-451a for the treatment of endometriosis in a murine model. Endometriosis was treated using a microRNA 451a inhibitor or a scrambled control microRNA. Treatment with miR-451a inhibitor resulted in reduced endometriosis lesion size (30 vs 13 mm³). There was no difference in the number of visible lesions between the miR-451a treatment and controls. Treatment led to altered expression of several genes including YWHAZ, CAB39, MAPK1, β-catenin, and IL-6. Systemic treatment with a miR-451a inhibitor is a promising therapy for endometriosis that simultaneously affects multiple pathways driving the disease.