Estrogen and progesterone receptor isoform distribution through the menstrual cycle in uteri with and without adenomyosis

Overview of crosstalk between stromal and epithelial cells in the pathogenesis of adenomyosis and shared features with deep endometriotic nodules

Since the first description of adenomyosis more than 150 years ago, multiple hypotheses have attempted to explain its pathogenesis. Indeed, research over recent years has greatly enhanced our knowledge of the underlying causes. This has opened up avenues for the development of strategies for both disease prevention and treatment of its main symptoms, such as pelvic pain, heavy menstrual bleeding, and infertility. However, the current means are still largely ineffective, so it is vital that we shed light on the pathways involved. Dysregulated mechanisms and aberrant protein expression have been identified as contributing factors in interactions between endometrial epithelial and stromal cells, ultimately leading to the growth of adenomyotic lesions. These include collective cell migration, epithelial-to-mesenchymal transition, hormonal influence, and signaling from non-coding RNAs and extracellular vesicles. We provide a concise summary of the latest insights into the crosstalk between glands and stroma in ectopic adenomyotic lesion formation. While there is an abundance of literature on similarities between adenomyosis and deep endometriosis, there are insufficient data on the cytochemical, molecular, and pathogenetic mechanisms of these two disorders. However, various shared features, including alterations of cell adhesion molecules, abnormal hormone regulation, and the presence of cancer-driving mutations and epigenetic modifications, have been identified. Nevertheless, the pathogenic mechanisms that contribute to the cause and development of these enigmatic diseases have not been fully elucidated yet.

Improvement of early miscarriage rates in women with adenomyosis via oxytocin receptor antagonist during frozen embryo transfer-a propensity score-matched study

BACKGROUND

Dysfunctional uterine peristalsis seems to play a pivotal role in hindering embryo implantation among women diagnosed with adenomyosis. This research aims to investigate whether administering an oxytocin receptor antagonist during a frozen embryo transfer (FET) cycle using a hormone replacement therapy (HRT) protocol can enhance in vitro fertilization (IVF) outcomes for infertile women affected by adenomyosis.

METHODS

Between January 2018 and June 2022, our reproductive center conducted IVF-FET HRT cycles for infertile women diagnosed with adenomyosis. Propensity score matching was employed to select matched subjects between the two groups in a 1:1 ratio. Following this, 168 women received an oxytocin receptor antagonist during FET, constituting the study group, while the matched 168 women underwent FET without this antagonist, forming the control group. We conducted comparative analyses of baseline and cycle characteristics between the two groups, along with additional subgroup analyses.

RESULTS

The study group exhibited notably lower rates of early miscarriage compared to the control group, although there were no significant differences in clinical pregnancy rates, ongoing pregnancy rates, and live birth rates between the two groups. Multivariate analysis revealed a negative correlation between the use of oxytocin receptor antagonists and early miscarriage rates in women with adenomyosis. Subgroup analyses, categorized by age, infertility types, and embryo transfer day, showed a substantial decrease in early miscarriage rates within specific subgroups: women aged ≥ 37 years, those with secondary infertility, and individuals undergoing day 3 embryo transfers in the study group compared to the control group. Furthermore, subgroup analysis based on adenomyosis types indicated significantly higher clinical pregnancy rates, ongoing pregnancy rates and live birth rates in the study group compared to the control group among women with diffuse adenomyosis.

CONCLUSIONS

Administering an oxytocin receptor antagonist during FET may reduce the early miscarriage rates in women with adenomyosis.

Long-Term Maintenance of Viable Human Endometrial Epithelial Cells to Analyze Estrogen and Progestin Effects

There are fewer investigations conducted on human primary endometrial epithelial cells (HPEECs) compared to human primary endometrial stromal cells (HPESCs). One of the main reasons is the scarcity of protocols enabling prolonged epithelial cell culture. Even though it is possible to culture HPEECs in 3D over a longer period of time, it is technically demanding. In this study, we successfully established a highly pure, stable, and long-term viable human conditionally reprogrammed endometrial epithelial cell line, designated as eCRC560. These cells stained positive for epithelial markers, estrogen and progesterone receptors, and epithelial cell-cell contacts but negative for stromal and endothelial cell markers. Estradiol (ES) reduced the abundance of ZO-1 in a time- and dose-dependent manner, in contrast to the dose-dependent increase with the progestin dienogest (DNG) when co-cultured with HPESCs. Moreover, ES significantly increased cell viability, cell migration, and invasion of the eCRC560 cells; all these effects were inhibited by pretreatment with DNG. DNG withdrawal led to a significantly disrupted monolayer of eCRC560 cells in co-culture with HPESCs, yet it markedly increased the adhesion of eCRC560 to the human mesothelial MeT-5A cells. The long-term viable eCRC560 cells are suitable for in vitro analysis of HPEECs to study the epithelial compartment of the human endometrium and endometrial pathologies.

Quantitative ultrasound measurement of uterine contractility in adenomyotic vs. normal uteri: a multicenter prospective study

OBJECTIVE

To evaluate uterine contractility in patients with adenomyosis compared with healthy controls using a quantitative two-dimensional transvaginal ultrasound (TVUS) speckle tracking method.

DESIGN

A multicenter prospective observational study took place in three European centers between 2014 and 2023.

SETTING

One university teaching hospital, 1 teaching hospital and 1 specialised clinic.

PATIENTS

A total of 46 women with a sonographic or magnetic resonance imaging diagnosis of adenomyosis were included. 106 healthy controls without uterine pathologies were included.

INTERVENTION

Four-minute TVUS recordings were performed and four uterine contractility features were extracted using a speckle tracking algorithm.

MAIN OUTCOMES MEASURES

The extracted features were contraction frequency (contractions/min), amplitude, velocity (mm/s), and coordination. Women with adenomyosis were compared with healthy controls according to the phase of the menstrual cycle.

RESULTS

Throughout the different phases of the menstrual cycle, trends of increased amplitude, decreased frequency and velocity, and reduced contraction coordination were seen in patients with adenomyosis compared with healthy controls. These were statistically significant in the late follicular phase, with a higher amplitude (0.087 ± 0.042 vs. 0.050 ± 0.018), lower frequency and velocity (1.49 ± 0.22 vs. 1.68 ± 0.25 contractions/min, and 0.65 ± 0.18 vs. 0.88 ± 0.29 mm/s, respectively), and reduced contraction coordination (0.34 ± 0.08 vs. 0.26 ± 0.17), in the late luteal phase, with higher amplitude (0.050 ± 0.022 vs. 0.035 ± 0.013), lower velocity (0.51 ± 0.11 vs. 0.65 ± 0.13 mm/s), and reduced contraction coordination (0.027 ± 0.06 vs. 0.18 ± 0.07), and in the midfollicular phase, with decreased frequency (1.48 ± 0.21 vs. 1.69 ± 0.16 contractions/min) in patients with adenomyosis compared with healthy controls. During menses, a higher pain score was significantly associated with lower frequency and velocity and higher contraction amplitude. Results remained significant after correcting for age, parity, and body mass index.

CONCLUSION

Uterine contractility differs in patients with adenomyosis compared with healthy controls throughout the phases of the menstrual cycle. This suggests an etiologic mechanism for the infertility and dysmenorrhea seen in patients with adenomyosis. Moreover, it presents new potential therapeutic targets and diagnostic markers.

Macrophage polarization in adenomyosis: A review

Adenomyosis (AM) is a common gynecological disorder characterized by the presence of endometrial glands and stroma within the uterine myometrium. It is associated with abnormal uterine bleeding (AUB), dysmenorrhea, and infertility. Although several mechanisms have been proposed to elucidate AM, the exact cause and development of the condition remain unclear. Recent studies have highlighted the significance of macrophage polarization in the microenvironment, which plays a crucial role in AM initiation and progression. However, a comprehensive review regarding the role and regulatory mechanism of macrophage polarization in AM is currently lacking. Therefore, this review aims to summarize the phenotype and function of macrophage polarization and the phenomenon of the polarization of adenomyosis-associated macrophages (AAMs). It also elaborates on the role and regulatory mechanism of AAM polarization in invasion/migration, fibrosis, angiogenesis, dysmenorrhea, and infertility. Furthermore, this review explores the underlying molecular mechanisms of AAM polarization and suggests future research directions. In conclusion, this review provides a new perspective on understanding the pathogenesis of AM and provides a theoretical foundation for developing targeted drugs through the regulation of AAM polarization.

The "freeze-all" strategy seems to improve the chances of birth in adenomyosis-affected women

OBJECTIVE

To compare assisted reproductive technologies (ARTs) outcomes between fresh vs. freeze-all strategies in infertile women affected by adenomyosis.

DESIGN

A single-center observational study.

SETTINGS

University hospital-based research center.

PATIENTS

Adenomyosis-affected women undergoing blastocyst embryo transfer after in vitro fertilization and intracytoplasmic sperm injection between January 1, 2018, and November 31, 2021. The diagnosis of adenomyosis was based on imaging criteria (i.e., transvaginal ultrasound and/or magnetic resonance imaging).

INTERVENTION(S)

Women who underwent a freeze-all strategy were compared with those who underwent a fresh embryo transfer (ET) strategy.

MAIN OUTCOME MEASURE(S)

Cumulative live birth rate (LBR).

RESULTS

A total of 306 women were included in the analysis: 111 in the fresh ET group and 195 in the freeze-all group. The adenomyosis phenotype (internal diffuse adenomyosis, external focal adenomyosis, and adenomyoma) was not significantly different between the two groups. The cumulative LBR (86 [44.1%] vs. 34 [30.6%], respectively), and the cumulative ongoing pregnancy rate (88 [45.1%] vs. 36 [32.4%], respectively) were significantly higher in the freeze-all group compared with the fresh ET group. After multivariate logistic regression analysis, the freeze-all strategy in women with adenomyosis was associated with significantly higher odds of live birth compared with fresh ET (odds ratio = 1.80; 95% confidence interval = 1.02-3.16).

CONCLUSION

The freeze-all strategy in women afflicted with adenomyosis undergoing ART was associated with significantly higher cumulative LBRs. Our preliminary results suggest that the freeze-all strategy is an attractive option that increases ART success rates. Additional studies, with a randomized design, should be conducted to further test whether the freeze-all strategy enhances the pregnancy rate in adenomyosis-affected women.

Establishment of an immortalized cell line derived from human adenomyosis ectopic lesions

Because adenomyosis (AM) ectopic primary cells are hard to come by, have a short lifespan, and the characteristics that alter over time, their utility in AM research is constrained. This study aimed to establish a line of immortalized human adenomyosis ectopic cell (ihAMEC) to change this situation. Primary cells were obtained from AM ectopic lesion tissue and then infected with Simian Vacuolating Virus 40 Tag (SV40 T) lentivirus and screened to establish immortalized cells. We verified the main features and found that the ihAMEC could be cultured for more than 50 generations and the proliferation ability of ihAMEC was more active than that of primary cells. The cytoskeleton and cell types of ihAMEC were similar to primary cells and maintained a normal karyotype. The expression of epithelial-mesenchymal transition (EMT) markers, estrogen-metabolizing proteins, and estrogen/progesterone receptors in ihAMEC was similar to the expression seen in primary cells. In addition, the response of ihAMEC under estrogen treatment and Lipopolysaccharide intervention is similar to primary cells. The clonogenic ability of ihAMEC was lower than tumor cells and did not form tumors in tumorigenicity assays. Thus, ihAMEC can be used as in vitro cellular model for pathogenesis and drug development studies regarding AM.

Current Medical Therapy for Adenomyosis: From Bench to Bedside

Adenomyosis, characterized by the growth of endometrial tissue within the uterine wall, poses significant challenges in treatment. The literature primarily focuses on managing abnormal uterine bleeding (AUB) and dysmenorrhea, the main symptoms of adenomyosis. Nonsteroidal anti-inflammatory drugs (NSAIDs) and tranexamic acid provide limited support for mild symptoms or symptom re-exacerbation during hormone therapy. The levonorgestrel-releasing intrauterine system (LNG-IUS) is commonly employed in adenomyosis management, showing promise in symptom improvement and reducing uterine size, despite the lack of standardized guidelines. Dienogest (DNG) also exhibits potential benefits, but limited evidence hinders treatment recommendations. Danazol, while effective, is limited by androgenic side effects. Combined oral contraceptives (COCs) may be less effective than progestins but can be considered for contraception in young patients. Gonadotropin-releasing hormone (GnRH) agonists effectively manage symptoms but induce menopausal symptoms with prolonged use. GnRH antagonists are a recent option requiring further investigation. Aromatase inhibitors (AIs) show promise in alleviating AUB and pelvic pain, but their safety necessitates exploration and limited use within trials for refractory patients. This review highlights the complexity of diagnosing adenomyosis, its coexistence with endometriosis and uterine leiomyomas, and its impact on fertility and quality of life, complicating treatment decisions. It emphasizes the need for research on guidelines for medical management, fertility outcomes, long-term effects of therapies, and exploration of new investigational targets. Future research should optimize therapeutic strategies, expand our understanding of adenomyosis and its management, and establish evidence-based guidelines to improve patient outcomes and quality of life.

Exosomes: potential diagnostic markers and drug carriers for adenomyosis

Adenomyosis is a common benign gynecological disorder and an important factor leading to infertility in fertile women. Adenomyosis can cause deep lesions and is persistent and refractory in nature due to its tumor-like biological characteristics, such as the ability to implant, adhere, and invade. The pathogenesis of adenomyosis is currently unclear. Therefore, new therapeutic approaches are urgently required. Exosomes are nanoscale vesicles secreted by cells that carry proteins, genetic materials and other biologically active components. Exosomes play an important role in maintaining tissue homeostasis and regulating immune responses and metabolism. A growing body of work has shown that exosomes and their contents are key to the development and progression of adenomyosis. This review discusses the current research progress, future prospects and challenges in this emerging therapeutic tool by providing an overview of the changes in the adenomyosis uterine microenvironment and the biogenesis and functions of exosomes, with particular emphasis on the role of exosomes and their contents in the regulation of cell migration, proliferation, fibrosis formation, neovascularization, and inflammatory responses in adenomyosis.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

CONCLUSIONS

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

FUNDING

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

Comparing MitoQ10 and heat therapy: Evaluating mechanisms and therapeutic potential for polycystic ovary syndrome induced by circadian rhythm disruption

Environmental factors, such as sleep restriction, contribute to polycystic ovary syndrome (PCOS) by causing hyperinsulinemia, hyperandrogenism, insulin resistance, and oligo- or anovulation. This study aimed to evaluate the effects of circadian rhythm disruption on reproductive and metabolic functions and investigate the potential therapeutic benefits of MitoQ10 and hot tub therapy (HTT). Sixty female rats were divided into six groups: control, MitoQ10, HTT, and three groups with PCOS induced by continuous light exposure(L/L). The reproductive, endocrine, and structural manifestations ofL/L-induced PCOS were confirmed by serum biochemical measurements, ultrasound evaluation of ovarian size, and vaginal smear examination at week 14. Subsequently, the rats were divided into the L/L (untreated), L/L+MitoQ10-treated, andL/L+HTT-treated groups. At the end of week 22, all rats were sacrificed. Treatmentwith MitoQ10 or HTT partially reversed the reproductive, endocrine, and structural features of PCOS, leading to a decreased amplitude of isolated uterine contractions, ovarian cystic changes and size, and endometrial thickness. Furthermore, both interventions improved the elevated serum levels of anti-Mullerian hormone (AMH), kisspeptin, Fibulin-1, A disintegrin and metalloproteinase with thrombospondin motifs 19 (ADAMTS-19), lipid profile, homeostatic model assessment for insulin resistance (HOMA-IR), oxidative stress markers, androgen receptors (AR) and their transcription target genes, FKBP52 immunostaining in ovarian tissues, and uterine estrogen receptor alpha (ER-α) and PRimmunostaining. In conclusion, MitoQ10 supplementation and HTT demonstrated the potential for ameliorating metabolic, reproductive, and structural perturbations associated with PCOS induced by circadian rhythm disruption. These findings suggest a potential therapeutic role for these interventions in managing PCOS in women.

Characterising the immune cell phenotype of ectopic adenomyosis lesions compared with eutopic endometrium: A systematic review

Inflammation is implicated in the symptomatology and the pathogenesis of adenomyosis. Injury at the endo-myometrial interface causes inflammation and may facilitate the invasion of endometrium into the myometrium, forming adenomyosis lesions. Their presence causes local inflammation, resulting in heavy menstrual bleeding, chronic pelvic pain, and subfertility. Immunological differences have been described in the eutopic endometrium from women with adenomyosis compared to healthy endometrium, and differences are also expected in the adenomyotic lesions compared with the correctly sited eutopic endometrium. This systematic review retrieved relevant articles from three databases with additional manual citation chaining from inception to 24th October 2022. Twenty-two eligible studies were selected in accordance with PRISMA guidelines. Risk of bias assessments were performed, and the findings presented thematically. Ectopic endometrial stroma contained an increased density of macrophages compared with eutopic endometrium in adenomyosis. This was associated with an increase in pro-inflammatory cytokines (IL-6, IL-8, ILβ-1, C-X-C Motif Chemokine Receptor 1(CXCR1), Monocyte Chemoattractant Protein-1 (MCP-1)), and an imbalance of anti-inflammatory cytokines (IL-22, IL-37). Cells in ectopic lesions also contained a higher levels of toll-like receptors and immune-mediated enzymes. However, the studies were heterogeneous, with inconsistent reporting of immune cell density within epithelial or stromal compartments, and inclusion of samples from different menstrual cycle phases in the same group for analysis. A detailed understanding of the immune cell phenotypes present in eutopic and ectopic endometrium in adenomyosis and associated dysregulated inflammatory processes will provide further insight into the pathogenesis, to enable identification of fertility-sparing treatments as an alternative to hysterectomy.

Molecular Targets for Nonhormonal Treatment Based on a Multistep Process of Adenomyosis Development

Adenomyosis is an estrogen-dependent gynecologic disease characterized by the presence of endometrial tissue within the myometrium. Adenomyosis presents with abnormal uterine bleeding, pelvic pains, and infertility. This review aimed to investigate the major estrogen downstream effectors involved in the process of adenomyosis development and their potential use for nonhormonal treatment. A literature search was performed for preclinical and clinical studies published between January 2010 and November 2021 in the PubMed and Google Scholar databases using a combination of specific terms. Adenomyosis presents with a wide spectrum of clinical manifestations from asymptomatic to severe through a complex process involving a series of molecular changes associated with inflammation, invasion, angiogenesis, and fibrosis. Adenomyosis may develop through a multistep process, including the acquisition of (epi)genetic mutations, tissue injury caused at the endometrial-myometrial interface, inside-to-outside invasion (from the endometrial side into the uterine wall), or outside-to-inside invasion (from the serosal side into the uterine wall), and epithelial-mesenchymal transition, tissue repair or remodeling in the myometrium. These processes can be regulated by increased estrogen biosynthesis and progesterone resistance. The expression of estrogen downstream effectors associated with persistent inflammation, fragile and more permeable vessel formation, and tissue injury and remodeling may be correlated with dysmenorrhea, heavy menstrual bleeding, and infertility, respectively. Key estrogen downstream targets (e.g., WNT/β-catenin, transforming growth factor-β, and nuclear factor-κB) may serve as hub genes. We reviewed the molecular mechanisms underlying the development of adenomyosis and summarized potential nonhormonal therapies.

The Role of Platelets in the Pathogenesis and Pathophysiology of Adenomyosis

Widely viewed as an enigmatic disease, adenomyosis is a common gynecological disease with bewildering pathogenesis and pathophysiology. One defining hallmark of adenomyotic lesions is cyclic bleeding as in eutopic endometrium, yet bleeding is a quintessential trademark of tissue injury, which is invariably followed by tissue repair. Consequently, adenomyotic lesions resemble wounds. Following each bleeding episode, adenomyotic lesions undergo tissue repair, and, as such, platelets are the first responder that heralds the subsequent tissue repair. This repeated tissue injury and repair (ReTIAR) would elicit several key molecular events crucial for lesional progression, eventually leading to lesional fibrosis. Platelets interact with adenomyotic cells and actively participate in these events, promoting the lesional progression and fibrogenesis. Lesional fibrosis may also be propagated into their neighboring endometrial-myometrial interface and then to eutopic endometrium, impairing endometrial repair and causing heavy menstrual bleeding. Moreover, lesional progression may result in hyperinnervation and an enlarged uterus. In this review, the role of platelets in the pathogenesis, progression, and pathophysiology is reviewed, along with the therapeutic implication. In addition, I shall demonstrate how the notion of ReTIAR provides a much needed framework to tether to and piece together many seemingly unrelated findings and how it helps to make useful predictions.

Immunohistochemical expression of Drosha is reduced in eutopic and ectopic endometrium of women with adenomyosis

The objective of this study was to evaluate the immunohistochemical expression of Dicer, Drosha, and Exportin-5 in the eutopic and ectopic endometrium of women with adenomyosis. Twenty-two paired ectopic and eutopic endometrium from women with adenomyosis and 10 eutopic endometrium samples from control women undergoing hysterectomy were included in the study. Paraffin-embedded tissue blocks were cut and stained for immunohistochemistry. The percentage of epithelial cells positively marked was identified digitally after an automated slide scanning process. Mann-Whitney test or Wilcoxon signed-rank test was performed for independent and paired groups, respectively. A lower expression of Drosha was observed in the eutopic endometrium of women with adenomyosis than in the eutopic endometrium of women without the disease (69.9±3.4% vs 85.2±2.9%, respectively) (P=0.016; 95%CI: 3.4 to 27.4%). We also detected lower Drosha expression in the ectopic endometrium of women with adenomyosis than in the eutopic endometrium of the same women (59.6±3.2% vs 69.9±3.4%, respectively) (P=0.004; 95%CI: 2.3 to 16.7%). Additionally, we observed a correlation between Drosha expression in the ectopic and paired eutopic endometrium (P=0.034, rho=0.454). No significant difference in Dicer or Exportin expression was observed. Predominant pattern of cytoplasmic staining for the anti-Drosha antibody and both a nuclear and cytoplasmic pattern for the anti-Exportin antibody were observed. Drosha expression was significantly lower in the endometrium of women with adenomyosis compared to the eutopic endometrium of asymptomatic women without the disease. Furthermore, its expression was lower in the ectopic endometrium but correlated to the paired eutopic endometrium.

Mechanism Study of Cinnamomi Ramulus and Paris polyphylla Sm. Drug Pair in the Treatment of Adenomyosis by Network Pharmacology and Experimental Validation

Objective. To explore the molecular mechanism of the Cinnamomi ramulus and Paris polyphylla Sm. (C-P) drug pair in the treatment of adenomyosis (AM) based on network pharmacology and animal experiments. Methods. Via a network pharmacology strategy, a drug-component-target-disease network (D-C-T-D) and protein–protein interaction (PPI) network were constructed to explore the core components and key targets of C-P drug pair therapy for AM, and the core components and key targets were verified by molecular docking. Based on the results of network pharmacology, animal experiments were performed for further verification. The therapeutic effect of the C-P drug pair on uterine ectopic lesions was evaluated in a constructed AM rat model. Results. A total of 30 components and 45 corresponding targets of C-P in the treatment of AM were obtained through network pharmacology. In the D-C-T-D network and PPI network, 5 core components and 10 key targets were identified. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that the PI3K signaling pathway was the most significantly enriched nontumor pathway. Molecular docking showed that most of the core components and key targets docked completely. Animal experiments showed that the C-P drug pair significantly ameliorated the pathological changes of endometriotic lesions in AM model rats and inhibited PI3K and Akt gene expression, and PI3K and Akt protein phosphorylation. In addition, treatment with the C-P drug pair promoted AM cell apoptosis; upregulated the protein expression of Bax, Caspase-3, and cleaved Caspase-9; and restrained Bcl-2 expression. Conclusions. We propose that the pharmacological mechanism of the C-P drug pair in the treatment of AM is related to inhibition of the PI3K/Akt pathway and promotion of apoptosis in AM ectopic lesions.

Functional Implications of Estrogen and Progesterone Receptors Expression in Adenomyosis, Potential Targets for Endocrinological Therapy

Adenomyosis is a common gynaecological disease associated with the presence of endometrial lesions in the uterine myometrium. Estrogens have been proven to be the crucial hormones driving the growth of adenomyosis. Little is known about the distinct mechanisms of progesterone action in adenomyosis. Hence, in this study, we decided to characterize the expression of all nuclear and membrane estrogen and progesterone receptors. Additionally, as a functional investigation, we monitored prolactin production and cell proliferation after estradiol and progesterone treatments. We confirmed the presence of all nuclear and membrane estrogen and progesterone receptors in adenomyotic lesions at gene and protein levels. The expression of membrane progesterone receptors α and β (mPRα, mPRβ) as well as estrogen receptor β (ERβ) was upregulated in adenomyosis compared to normal myometrium. Estradiol significantly increased adenomyotic cell proliferation. Progesterone and cAMP upregulated prolactin secretion in adenomyosis in the same pattern as in the normal endometrium. In the present study, we showed the functional link between estradiol action and adenomyotic cell proliferation, as well as progesterone and prolactin production. Our findings provide novel insights into the sex steroid receptor expression pattern and potential regulated pathways in adenomyosis, suggesting that all receptors play an important role in adenomyosis pathophysiology.

Pathogenesis of Human Adenomyosis: Current Understanding and Its Association with Infertility

The aim of this review article was to summarize our current understanding on the etiologies and pathogenesis of human adenomyosis and to clarify the relative association between adenomyosis and infertility. The exact pathogenesis of adenomyosis is still elusive. Among different reported concepts, direction invagination of gland cells from the basalis endometrium deep into myometrium is the most widely accepted opinion on the development of adenomyosis. According to this concept, endometrial epithelial cells and changed fibroblasts, abnormally found in the myometrium in response to repeated tissue injury and/or disruption at the endometrium-myometrium interface (EMI), elicit hyperplasia and hypertrophy of the surrounding smooth muscle cells. In this review, a comprehensive review was performed with a literature search using PubMed for all publications in English and Japanese (abstract in English), related to adenomyosis and infertility, from inception to April 2021. As an estrogen-regulated factor, hepatocyte growth factor (HGF) exhibits multiple functions in endometriosis, a disease commonly believed to arise from the functionalis endometrium. As a mechanistic basis of gland invagination, we investigated the role of HGF, either alone or in combination with estrogen, in the occurrence of epithelial-mesenchymal transition (EMT) in adenomyosis. Aside from microtrauma at the EMI, metaplasia of displaced Müllerian remnants, differentiation of endometrial stem/progenitor cells within the myometrium and somatic mutation of some target genes have been put forward to explain how adenomyosis develops. In addition, the possible role of microRNAs in adenomyosis is also discussed. Besides our knowledge on the conventional classification (focal and diffuse), two recently proposed classifications (intrinsic and extrinsic) of adenomyosis and the biological differences between them have been described. Although the mechanistic basis is unclear, the influence of adenomyosis on fertility outcome is important, especially considering the recent tendency to delay pregnancy among women. Besides other proposed mechanisms, a recent transmission election microscopic (TEM) study indicated that microvilli damage and an axonemal alteration in the apical endometria of human adenomyosis, in response to endometrial inflammation, may be involved in negative fertility outcomes. We present a critical analysis of the literature data concerning the mechanistic basis of infertility in women with adenomyosis and its impact on fertility outcome.

Uterine bleeding: how understanding endometrial physiology underpins menstrual health

Menstruation is a physiological process that is typically uncomplicated. However, up to one third of women globally will be affected by abnormal uterine bleeding (AUB) at some point in their reproductive years. Menstruation (that is, endometrial shedding) is a fine balance between proliferation, decidualization, inflammation, hypoxia, apoptosis, haemostasis, vasoconstriction and, finally, repair and regeneration. An imbalance in any one of these processes can lead to the abnormal endometrial phenotype of AUB. Poor menstrual health has a negative impact on a person's physical, mental, social, emotional and financial well-being. On a global scale, iron deficiency and iron deficiency anaemia are closely linked with AUB, and are often under-reported and under-recognized. The International Federation of Gynecology and Obstetrics have produced standardized terminology and a classification system for the causes of AUB. This standardization will facilitate future research endeavours, diagnosis and clinical management. In a field where no new medications have been developed for over 20 years, emerging technologies are paving the way for a deeper understanding of the biology of the endometrium in health and disease, as well as opening up novel diagnostic and management avenues.

Nuclear receptor coactivator-6 is essential for the morphological change of human uterine stromal cell decidualization via regulating actin fiber reorganization

Nuclear receptor coactivator 6 (Ncoa6), a modulator of several nuclear receptors and transcription factors, is essential for the decidualization of endometrial stromal cells in mice. However, the function of Ncoa6 in the human endometrium remains unclear. We investigated its function in the decidualization of human endometrial stromal cells (HESCs) isolated from resected uteri. Knockdown of Ncoa6 was performed using two independent small interfering RNAs. Decidualization was induced in vitro via medroxyprogesterone and cyclic adenosine monophosphate. We compared decidualized cellular morphology between the Ncoa6 knockdown cells and control cells. Messenger RNA (mRNA) sequencing was performed to determine the Ncoa6 target genes in undecidualized HESCs. We found that the knockdown of Ncoa6 caused the failure of morphological changes in decidualized HESCs compared to that in the control cells. mRNA sequencing revealed that Ncoa6 regulates the expression of genes associated with the regulation of actin fibers. Ncoa6 knockdown cells failed to reorganize actin fibers during the decidualization of HESCs. Ncoa6 was shown to play an essential role in decidualization via the appropriate regulation of actin fiber regulation in HESCs. Herein, our in vitro studies revealed a part of the mechanisms involved in endometrial decidualization. Future research is needed to investigate these mechanisms in women with implantation defects.

Mechanisms and Pathogenesis of Adenomyosis

Purpose of the Review

The purpose of this review is to provide a synopsis of all the mechanisms involved in the pathogenesis of adenomyosis. It will summarize recent advances in the field, discussing current controversies, and considering potential future directions.

Recent Findings

Adenomyosis pathogenesis is still a topic under investigation, however advancements in the understanding of disease development and mechanisms have been made. New data coming from new next generation sequencing-based studies and more-in-depth acquisitions on sex hormones imbalance, neuroangiogenesis, inflammation, fibrosis and cell proliferation have been obtained.

Summary

Adenomyosis is a uterine disorder that affects women of reproductive age, characterized by a benign invasion of the endometrium basalis (glands and stroma) within the myometrium.

So far, three theories for the pathophysiology of adenomyosis have been proposed:

In order to invade and develop, endometrial cells require a series of pathogenetic mechanisms which drive to adenomyosis. Altered sex steroids hormones receptors may be the primary event which causes increased endometrial cell proliferations and differentiation from epithelial to mesenchymal cells. Once invaded the myometrium, an inflammatory reaction is displayed, probably driven by local immune changes. The processes of neuroangiogenesis and fibrosis are also involved in the adenomyosis development and may explain some of the associated clinical symptoms (dysmenorrhea, abnormal uterine bleeding, and infertility).

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.

Uterine Adenomyosis Treated by Linzagolix, an Oral Gonadotropin-Releasing Hormone Receptor Antagonist: A Pilot Study with a New 'Hit Hard First and then Maintain' Regimen of Administration

(1) Background: The aim of the present pilot study was to study the effect of a new oral gonadotropin-releasing hormone antagonist on adenomyosis. (2) Methods: Eight premenopausal women, aged between 37 and 45 years, presenting with heavy menstrual bleeding, pelvic pain, and dysmenorrhea due to diffuse and disseminated uterine adenomyosis, confirmed by magnetic resonance imaging (MRI), received 200 mg linzagolix once daily for a period of 12 weeks, after which they were switched to 100 mg linzagolix once daily for another 12 weeks. The primary efficacy endpoint was the change in volume of the adenomyotic uterus from baseline to 24 weeks, evaluated by MRI. Secondary efficacy endpoints included the change in uterine volume from baseline to 12 and 36 weeks by MRI, and also weeks 12, 24, and 36 assessed by transvaginal ultrasound (TVUS). Other endpoints were overall pelvic pain, dysmenorrhea, non-menstrual pelvic pain, dyspareunia, amenorrhea, quality of life measures, bone mineral density (BMD), junctional zone thickness, and serum estradiol values. (3) Results: Median serum estradiol was suppressed below 20 pg/mL during the 12 weeks on linzagolix 200 mg, and maintained below 60 pg/mL during the second 12 weeks on linzagolix 100 mg. At baseline, the mean ± SD uterine volume was 333 ± 250 cm³. After 24 weeks of treatment, it was 204 ± 126 cm³, a reduction of 32% (p = 0.0057). After 12 weeks, the mean uterine volume was 159 ± 95 cm³, a reduction of 55% from baseline (p = 0.0001). A similar pattern was observed when uterine volume was assessed by TVUS. Improvements in overall pelvic pain, dysmenorrhea, non-menstrual pelvic pain, dyspareunia, and dyschezia, as well as quality of life measured using the EHP-30 were also observed. Mean percentage BMD loss at 24 weeks was, respectively, -2.4%, -1.3%, and -4.1% for the spine, femoral neck, and total hip. The most common adverse events were hot flushes, which occurred in 6/8 women during the first 12 weeks, and 1/8 women between 12 and 24 weeks. (4) Conclusions: Linzagolix at a dose of 200 mg/day reduced uterine volume, and improved clinically relevant symptoms. Treatment with 100 mg thereafter retains the therapeutic benefits of the starting dose while minimizing side effects. This 'hit hard first and then maintain' approach may be the optimal way to treat women with symptomatic adenomyosis.

Scribble downregulation in adenomyosis compromises endometrial stromal decidualization by decreasing FOXO1 expression

STUDY QUESTION

Does Scribble (SCRIB) contribute to aberrant decidualization of endometrial stromal cells (ESC) in adenomyosis?

SUMMARY ANSWER

SCRIB knockdown impairs decidualization of ESC by decreasing Fork-head box O1A (FOXO1) expression through the protein kinase B (AKT) and atypical protein kinase C (aPKC) activated pathways.

WHAT IS KNOWN ALREADY

Stromal SCRIB is required for primary decidual zone formation and pregnancy success in mice. In our previous studies, decidualization was dampened in ESC isolated from adenomyosis patients, yet the underlying molecular mechanisms remain elusive.

STUDY DESIGN, SIZE, DURATION

Eutopic endometrium tissue samples from diffuse adenomyosis and non-adenomyosis patients in proliferative, early-secretory and mid-secretory phase (n = 10 per phase for each group) were explored. In parallel, in vitro decidualization studies were carried out in ESC isolated from non-adenomyosis women (n = 8).

PARTICIPANTS/MATERIALS, SETTING, METHODS

The endometrial SCRIB expression was analyzed using immunohistochemistry staining and western blot. Quantitative RT-PCR (qRT-PCR), western blot and immunofluorescence staining were used to explore the expression of SCRIB in ESC during in vitro decidualization. siRNA-mediated SCRIB knockdown followed by decidual markers expression analysis, flow cytometry for cell cycle analysis and phalloidin staining for morphological analysis were performed to examine the function of SCRIB in ESC decidualization. RNA-sequencing was performed to examine the SCRIB-mediated transcriptional changes in decidualized ESC (DSC). Rescue experiments using an AKT inhibitor MK2206 and aPKC inhibitor NSC37044 were used to investigate the signaling pathways through which could mediate SCRIB-regulated FOXO1 protein expression and ESC decidualization.

MAIN RESULTS AND THE ROLE OF CHANCE

We found that the expression of SCRIB in the mid-secretory phase eutopic endometrial stroma of adenomyosis patients was significantly lower than that of non-adenomyosis. SCRIB knockdown reduced the expression of decidual markers, abrogated the epithelioid-like morphological changes, inhibited the mesenchymal-to-epithelial transitions process and promoted the cell cycle progression of ESC during in vitro decidualization. SCRIB knockdown-induced decidualization defects were attributed to a decrease in expression of transcription factor FOXO1, known to regulate decidualization. Furthermore, we found that SCRIB knockdown induced the aberrant activation of AKT and aPKC, which led to FOXO1 phosphorylation and degradation. Rescue assay confirmed that restoring the expression of FOXO1 effectively reversed the decidualization defects and cell cycle progression caused by SCRIB knockdown.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

In this study, it was demonstrated that SCRIB knockdown mediated the activation of AKT and aPKC, contributing to FOXO1 degradation and aberrant decidualization, however, the molecular link between AKT and aPKC signaling was not determined, and still requires further exploration.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings support the hypothesis that adenomyosis interferes with embryo implantation due to insufficient endometrial receptivity. Abnormal decidualization of the endometrial stroma may clarify the possible association between adenomyosis and infertility. Our findings may be clinically useful for counseling and treatment of infertile adenomyosis patients.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the National Natural Science Foundation of China (82001523 and 82171639). The authors have no conflicts of interest to disclose.

TRIAL REGISTRATION NUMBER

N/A.

[Adenomyosis pathophysiology: An unresolved enigma]

Adenomyosis is a chronic benign uterine disease characterized by the presence of endometrial glands and stroma within the myometrium. It is a heterogeneous disease, presenting various clinical forms, depending on the location of the ectopic lesions within the myometrium. Adenomyosis can be responsible for several symptoms such as dysmenorrhea, abnormal uterine bleeding and/or infertility. Its pathophysiology is a real conundrum and several theories have been proposed: development of adenomyosis lesion could initiate de novo from Mullerian rests or from stem cells. Moreover, multiple factors could be involved in initiating lesions, including specific hormonal, immune and/or genetic changes. The objective of this review is to provide an update on adenomyosis pathophysiology, in particular on the various theories proposed concerning the invasion of the myometrium by endometrial cells and the inducing mechanisms, and to study the link between the physiopathology, the symptoms and the medical treatments.

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

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

The Role of Abnormal Uterine Junction Zone in the Occurrence and Development of Adenomyosis

Adenomyosis is a benign disease with a malignant behavior, bothering a lot of women at reproductive age who suffer from increased menstruation, prolonged menstruation, progressive dysmenorrhea, and infertility. At present, there is no effective treatment for adenomyosis. It seriously affects the life quality of these patients. However, the pathogenesis of adenomyosis is not yet clear. Recently, uterus junctional zone, defined as the inner 1/3 of myometrium between endometrium and myometrium, has gained broad attention. As is reported, the structure and function disorder of uterus junctional zone may play an important part in the occurrence and development of adenomyosis. In this issue, the present study generally reviews the role of uterine junction zone and the related mechanisms involved in adenomyosis, such as the local micro-damage, the formation of inflammatory and hypoxic microenvironment, changes of cytokines, and abnormalities of miRNA as well as signal pathways. It will provide new insights and potential therapeutic target strategies for clinical strategies in the management of adenomyosis.

Adenomyosis and infertility: the role of the junctional zone

OBJECTIVE

Adenomyosis is a benign uterine disorder characterized by the invasion of the endometrium within the myometrium, starting from the junctional zone (JZ), the inner hormone dependent layer of the myometrium that plays an important role in sperm transport, implantation and placentation. The resulting histological abnormalities and functional defects may represent the pathogenic substrate for infertility and pregnancy complications. The objective of this paper is to review the literature to evaluate the correlation between inner myometrium alterations and infertility and to assess the role of JZ in the origin of adverse obstetric outcomes of both spontaneous and in vitro fertilization (IVF) pregnancies.

METHODS

we searched Pubmed for all original and review articles in the English language from January1962 until December 2019, using the MeSH terms of 'adenomyosis', 'junctional zone', combined with 'infertility', 'obstetrical outcomes', 'spontaneous conception', 'in vitro fertilization' and 'classification'. The review was divided into three sections to assess this pathogenic correlation, evaluating also the importance of classification of the disease.

RESULTS AND CONCLUSIONS

Absent or incomplete remodeling of the JZ can affect uterine peristalsis, alter vascular plasticity of the spiral arteries and activate inflammatory pathways, all related to adverse obstetric outcomes. Despite these observations, there is still limited evidence whether adenomyosis is a cause of infertility. However, it is reasonable to screen patients for adenomyosis, to consider pregnant women with diffuse adenomyosis at high risk of adverse obstetric outcomes, and to evaluate the importance of a noninvasive validated classification in the management of women with adenomyosis.

Adenomyosis pathogenesis: insights from next-generation sequencing

BACKGROUND

Adenomyosis, characterized by the presence of islands of endometrial tissue surrounded by hypertrophic smooth muscle cells within the myometrium, is one of the most challenging uterine disorders in terms of diagnosis and management. Adenomyosis presents with pelvic pain, excessive uterine bleeding, anemia and infertility. The relative contributions of abnormal endometrial tissue and myometrial smooth muscle cells to the development and growth of adenomyosis are not well understood. Moreover, there is continuing debate on the origins of adenomyosis; two competing theories describe the invagination of basal endometrium into the myometrium or the metaplastic differentiation of remnant endometrial stem/progenitor cells within the myometrium.

OBJECTIVE AND RATIONALE

A recent series of next-generation sequencing (NGS) studies have provided the best scientific evidence thus far regarding the cellular origins of adenomyosis and the contributions of new signaling pathways to its pathogenesis, survival, and growth. These seminal studies on endometrium, adenomyosis and endometriosis demonstrate or support the following key points. (i) Mutations of KRAS map to both intracavitary endometrial tissue and proximally located adenomyotic samples, supporting the invagination theory of pathogenesis. Driver mutations found in smooth muscle cells of uterine fibroids are absent in adenomyosis. (ii) KRAS and other less frequent mutations are limited to endometrial-type epithelial cells. They are also observed in endometriosis, indicating that the disease process in adenomyosis is similar to that in endometriosis and distinct from that of uterine fibroids. (iii) Activating mutations of KRAS stimulate specific pathways to increase cell survival and proliferation and are associated with progesterone resistance in adenomyosis. Together, these findings suggest that distinct cell populations in eutopic endometrial tissue play key roles in the etiology of adenomyosis. Dependence on ovarian steroids and ovulatory cycles for disease severity is a unique feature of adenomyosis. In this context, common patterns of aberrant gene expression have been reported both in adenomyosis and endometriosis. These include pathways that favor increased estrogen biosynthesis, decreased estradiol metabolism, a unique estrogen receptor beta (ESR2)-driven inflammatory process, and progesterone resistance due to decreased progesterone receptor expression. Since adenomyosis exhibits a uniquely estrogen-driven inflammatory process and progesterone resistance, we discuss the interactions between these molecular characteristics and signaling pathways induced by the newly discovered KRAS mutations.

SEARCH METHODS

We conducted a comprehensive search using PubMed for human and animal studies published until 2020 in the following areas: adenomyosis, endometriosis, endometrium, NGS, whole-exome sequencing, whole-genome sequencing, RNA sequencing, targeted deep sequencing, epigenetics, driver mutation, KRAS, progesterone resistance, estrogen action and steroid production.

OUTCOMES

Targeted deep sequencing analyses of epithelial cells in adenomyosis and adjacent basalis endometrial glands demonstrated recurring KRAS mutations in both cell types. This finding suggests that adenomyosis originates from basalis endometrium. Epithelial cells of the endometrium, adjacent adenomyosis and co-occurring endometriosis also share identical KRAS mutations. These findings suggest both adenomyosis and endometriosis are oligoclonal tissues that arise from endometrial cell populations carrying a specific driver mutation that most commonly affects the KRAS gene.

WIDER IMPLICATIONS

Adenomyosis usually follows an event such as pregnancy that has disrupted the integrity of the endometrial–myometrial junction followed by repetitious menstrual episodes that increase the likelihood of the entrapment of the basalis endometrium within the myometrium. Glandular epithelial cells carrying KRAS mutations and located within the deep crypts of basalis endometrium may become entrapped and invade myometrial tissue to give rise to adenomyosis. Evidence suggests that KRAS mutations may be responsible, in part, for previously observed phenomena such as prolonged cell survival and progesterone resistance in adenomyosis.

Impaired decidualization of human endometrial stromal cells from women with adenomyosis†

Differentiation of endometrial stromal cells (ESCs) into secretory decidualized cells (dESCs) is essential for embryo implantation. Adenomyosis is a common benign gynecological disease that causes infertility. However, whether adenomyosis affects decidualization of human ESCs is elusive. Primary eutopic ESCs were obtained from patients with adenomyosis (n = 9) and women with nonendometrial diseases (n = 12). We determined the capacity of decidualization of human ESCs by qRT-PCR, Edu proliferation assay, cytokine array, and ELISA assay. We found that the expression of decidualization markers (IGFBP1 and PRL) in ESCs of adenomyosis was reduced, concomitant with increased cell proliferation. Differential secretion of cytokines in dESCs, including CXCL1/2/3, IL-6, IL-8, MCP-1, VEGF-A, MIP-3α, OPN, SDF-1α, HGF, and MMP-9, was observed between adenomyosis and nonadenomyosis. Moreover, the expression of decidualization regulators (HOXA10 at both mRNA and protein levels, FOXO1, KLF5, CEBPB, and HAND2 at mRNA levels) in the eutopic endometrium of adenomyosis was lower than that of nonadenomyosis. We propose that ESCs from adenomyosis have defected ability to full decidualization, which may lead to a nonreceptive endometrium.

Adenomyosis and in vitro fertilization impacts - A literature review

Adenomyosis is a gynecological condition, which is characterized by stromal and glandular endometrial tissue infiltration inti the myometrium, resulting in an increase of uterine volume. The etiology of adenomyosis is presently unknown, but some theories assist us in understanding its pathogenesis and natural history. Clinical manifestations are increased menstrual flow and dysmenorrhea, abnormal uterine bleeding, chronic pelvic pain, and dyspareunia. The signs and symptoms suggestive of adenomyosis are complemented by diagnostic methods such as transvaginal ultrasound (TVUS), ideally with intestinal preparation, magnetic resonance imaging (MRI) and surgery; although currently, there are no precise criteria for the classification of findings on imaging studies. The clinical and surgical therapeutic approach must be individualized, taking into account the patient's characteristics, for instance, age, parity, depth and number of adenomyotic foci, uterine volume and, mainly, clinical manifestations. A causal relation between adenomyosis and infertility has been repeatedly suggested, mostly due to the anatomo-physiopathological conditions originated by the adenomyosis on the female genital tract; however, definitive conclusions are still lacking. This pathology is found in approximately 25% of infertile women, especially those who have had recurrent pregnancy loss (RPL), recurrent implantation failure, older women seeking In Vitro fertilization (IVF) treatment, and those with concomitant endometriosis. To determine whether adenomyosis per se affects fertility, several researchers have focused on women who are affected by the condition and underwent IVF/intracytoplasmic sperm injection (ICSI); for this model provides more accurate data about the influence of adenomyosis on embryo implantation. Therefore, our objective was to analyze, through a systematic literature review, the effect of uterine adenomyosis on the probability of pregnancy by IVF / ICSI, as well as trying to point out the main difficulties and gaps to establish a standard protocol for the management of these patients, since most of the patients with adenomyosis have other associated gynecological pathologies, mostly endometriosis; in addition to the heterogeneity of the studies still remaining as an obstacle to precise conclusions.

The Multifaceted Role of Autophagy in Endometrium Homeostasis and Disease

Autophagy is a conserved fundamental cellular process with a primary function of catabolizing harmful or surplus cellular contents such as protein aggregates, dysfunctional/long-lived organelles, intracellular pathogens, and storage nutrients. An increasing body of evidence reveals that basal autophagy is essential for maintaining endometrial homeostasis and mediating endometrial-specific functions, including menstrual cycle, embryo implantation, and decidualization. However, perturbed levels of autophagy can lead to severe endometrial pathologies, including endometriosis, endometrial hyperplasia, endometrial cancer, adenomyosis, and leiomyoma. This review highlights the most recent findings on the activity, regulation, and function of autophagy in endometrium physiology and pathology. Understanding the mechanistic roles of autophagy in endometrium homeostasis and disease is key to developing novel therapeutic strategies for endometrium-related infertility and malignancies.

In the mouse, prostaglandin D2 signalling protects the endometrium against adenomyosis

Adenomyosis is characterised by epithelial gland and mesenchymal stroma invasion of the uterine myometrium. Adenomyosis is an oestrogen-dependent gynaecological disease in which a number of factors, such as inflammatory molecules, prostaglandins (PGs), angiogenic factors, cell proliferation and extracellular matrix remodelling proteins, also play a role as key disease mediators. In this study, we used mice lacking both lipocalin and hematopoietic-PG D synthase (L- and H-Pgds) genes in which PGD2 is not produced to elucidate PGD2 roles in the uterus. Gene expression studied by real-time PCR and hormone dosages performed by ELISA or liquid chromatography tandem mass spectroscopy in mouse uterus samples showed that components of the PGD2 signalling pathway, both PGDS and PGD2-receptors, are expressed in the mouse endometrium throughout the oestrus cycle with some differences among uterine compartments. We showed that PGE2 production and the steroidogenic pathway are dysregulated in the absence of PGD2. Histological analysis of L/H-Pgds-/- uteri, and immunohistochemistry and immunofluorescence analyses of proliferation (Ki67), endothelial cell (CD31), epithelial cell (pan-cytokeratin), myofibroblast (α-SMA) and mesenchymal cell (vimentin) markers, identify that 6-month-old L/H-Pgds-/- animals developed adenomyotic lesions, and that disease severity increased with age. In conclusion, this study suggests that the PGD2 pathway has major roles in the uterus by protecting the endometrium against adenomyosis development. Additional experiments, using for instance transcriptomic approaches, are necessary to fully determine the molecular mechanisms that lead to adenomyosis in L/H-Pgds-/- mice and to confirm whether this strain is an appropriate model for studying the human disease.

Adenomyosis is associated with specific proton nuclear magnetic resonance (1H-NMR) serum metabolic profiles

OBJECTIVE

To determine whether the adenomyosis phenotype affects the proton nuclear magnetic resonance (¹H-NMR)-based serum metabolic profile of patients.

DESIGN

Cohort study.

SETTING

University hospital-based research center.

PATIENTS

Seventy-seven patients who underwent laparoscopy for a benign gynecologic condition.

INTERVENTIONS

Pelvic magnetic resonance imaging and collection of a venous peripheral blood sample were performed during the preoperative workup. The women were allocated to the adenomyosis group (n = 32), or the control group (n = 45). The adenomyosis group was further subdivided into two groups: diffuse adenomyosis of the inner myometrium (n = 14) and focal adenomyosis of the outer myometrium (n = 18). Other adenomyosis phenotypes were excluded.

MAIN OUTCOME MEASURES

Metabolomic profiling based on ¹H-NMR spectroscopy in combination with statistical approaches.

RESULTS

The serum metabolic profiles of the patients with adenomyosis indicated lower concentrations of 3-hydroxybutyrate, glutamate, and serine compared with controls. Conversely, the concentrations of proline, choline, citrate, 2-hydroxybutyrate, and creatinine were higher in the adenomyosis group. The focal adenomyosis of the outer myometrium and the diffuse adenomyosis phenotypes also each exhibited a specific metabolic profile.

CONCLUSION

Serum metabolic changes were detected in women with features of adenomyosis compared with their disease-free counterparts, and a number of specific metabolic pathways appear to be engaged according to the adenomyosis phenotype. The metabolites with altered levels are particularly involved in immune activation as well as cell proliferation and cell migration. Nevertheless, this study did find evidence of a correlation between metabolite levels and symptoms thought to be related to adenomyosis. Further studies are required to determine the clinical significance of these differences in metabolic profiles.

A Detailed Study in Adenomyosis and Endometriosis: Evaluation of the Rate of Coexistence Between Uterine Adenomyosis and DIE According to Imaging and Histopathology Findings

The current study was designed to evaluate the relationship between adenomyosis and its subtypes with endometriotic lesions (ovarian endometrioma (OMAs) and posterior deep infiltrative endometriosis (DIE)), to examine the probability of existence of a common cause of these mysterious diseases, and to evaluate the accuracy, sensitivity, and specificity of both transvaginal ultrasonography (TVS) and MRI in diagnosis of adenomyotic uterus. In this retrospective cross-sectional study, we selected 154 women with coexistence of endometriosis and adenomyosis according to their imaging, intraoperative, or pathological findings who were nominated for laparoscopic surgery. Eighty-six patients with just DIE resection without LH (laparoscopic hysterectomy) (group 1), and 68 patients with LH + DIE resection (group 2). The accuracy, sensitivity, and specificity of ultrasonographic and MRI findings for diagnosing adenomyosis were 72.1%, 77.6%, 40.0% and 49.2%, 41.5%, 90.0% respectively. So, TVS is a more sensitive diagnostic tool for diagnosing adenomyosis. However, MRI was more specific than TVS in the diagnosis of diffuse adenomyosis especially with simultaneous presence of uterine leiomyoma. Regarding the association of different types of adenomyosis (focal and diffuse) with different endometriosis lesions (OMA and posterior compartment DIE), we just found diffuse type of adenomyosis more frequent in the absence of rectal and rectovaginal septum (RVS) DIE (p ≤ 0.05). In addition to the questionable different nature of rectal and RVS DIE lesion, there is no relationship between adenomyosis subtypes and endometriotic lesions.

Talin1 Induces Epithelial-Mesenchymal Transition to Facilitate Endometrial Cell Migration and Invasion in Adenomyosis Under the Regulation of microRNA-145-5p

Adenomyosis (ADS) is a commonly encountered benign gynecological disorder. Epithelial-mesenchymal transition (EMT) may serve a pivotal role in the pathogenesis of ADS. Talin1 has been identified to be implicated in multiple human carcinomas, probably through inducing EMT process. However, available data on the precise molecular mechanism of Talin1 in the pathogenesis of ADS remain extremely scanty. In the present study, we aim to investigate the clinical roles of Talin1 and its effects on uterine endometrial cell migration, invasion, and EMT in ADS. Relative mRNA expression of Talin1, microRNA-145-5p (miR-145-5p), and EMT-related markers was determined by qRT-PCR. Immunohistochemistry and immunofluorescence were performed to examine the distribution of Talin1 in ADS endometrium. Protein levels of Talin1, EMT-related markers, and wnt/β-catenin pathway were measured by western blot. Wound healing assay and transwell assay were utilized for evaluating cell migration and invasion respectively. Dual-luciferase reporter assay was performed to verify the relationship between Talin1 and miR-145-5p. We found Talin1 was markedly overexpressed in ADS endometrial tissue and cells, whereas miR-145-5p was downregulated. Elevated Talin1 mRNA level might be closely related to some clinicopathological features of ADS. Through functional experiments, we demonstrated that overexpression of Talin1 induced EMT and enhanced migration and invasion ability of ADS eutopic and ectopic endometrial epithelial cells (ADS_Eu_EEC and ADS_Ec_EEC) in vitro through activating the canonical wnt/β-catenin pathway. From a mechanistic perspective, Talin1 was inversely regulated by miR-145-5p as a direct target. Our findings unveiled that under the regulation of miR-145-5p, Talin1 might promote endometrial cell migration and invasion through inducing EMT, presenting a novel insight for elucidating the pathogenesis of ADS.

Clinical outcomes after single-versus double-embryo transfers in women with adenomyosis: a retrospective study

BACKGROUND

Adenomyosis affects the outcomes of spontaneous fertility and assisted reproductive technology. The single blastocyst embryo transfer (SBT) policy is an effective strategy known to minimize the risk of multiple pregnancy for non-adenomyosis women. However, little is known about its applicability to women with adenomyosis. The purpose of this study is to compare pregnancy outcomes between SBT, double-blastocyst embryo transfer (DBT), single-cleavage-stage embryo transfer (SET) and double-cleavage-stage embryo transfer (DET) in the frozen-thawed embryo transfer cycles among adenomyosis patients.

METHODS

This retrospective study was conducted in all frozen-thawed autologous embryo transfer cycles. 393 frozen-thawed embryo transfer cycles performed in adenomyosis patients were enrolled. The major clinical outcomes were implantation rate (IR), clinical pregnancy rate (CPR), miscarriage rate (MR), multiple pregnancy rate (MPR) and live birth rate (LBR).

RESULTS

The SBT and DBT groups achieved higher IR (P < 0.001), CPR (P = 0.017), LBR (P = 0.040) and lower MR (P = 0.020) than the SET and DET groups. But the SBT and DBT groups achieved similar CPR and LBR. The SBT and SET groups achieved lower MPR (P < 0.001) than the DBT and DET groups. The average birth weight (BW) of SBT groups was higher than the DBT and DET groups (P = 0.016). When compared with SBT group, low-birth-weight infants were significantly higher with DBT and DET.

CONCLUSIONS

When performing frozen-thawed embryo transfer cycles among adenomyosis patients, the SBT group has similar IR, CPR, MR, LBR but lower MPR compared to the DBT group. Therefore, SBT might be offered as standard practice.

Polycystic Ovary Syndrome and the Forgotten Uterus

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

The freeze-all strategy after IVF: which indications?

The freeze-all strategy is gaining popularity worldwide as an alternative to the conventional fresh embryo transfer. It consists of cryopreservation of the entire embryo cohort and the embryo transfer in a subsequent cycle that takes place separately from ovarian stimulation. The freeze-all strategy was initially a 'rescue' strategy for women at high risk of ovarian hyperstimulation syndrome; however, this approach has been extended to other indications as a scheduled strategy to improve implantation rates. This assumes that ovarian stimulation can alter endometrial receptivity in fresh cycles owing to the effect of supraphysiological levels of steroids on endometrial maturation. The procedure, however, has not been associated with increased live birth rates in all infertile couples, and concerns have been raised about the occurrence of several adverse perinatal outcomes. It is, therefore, crucial to identify in which subgroups of patients a freeze-all strategy could be beneficial. The aim of this review is to summarize current scientific research in this field to highlight potential indications for this strategy and to guide clinicians in their daily practice.

Physiomimetic Models of Adenomyosis

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

Animal Models of Adenomyosis

Adenomyosis is a nonmalignant uterine disorder in which endometrial tissue exists within and grows into the myometrium. Animal models have generated limited insight into the still-unclear pathogenesis of adenomyosis, provided a platform for preclinical screening of many drugs and compounds with potential as therapeutics, and elucidated mechanisms underlying the pain and fertility issues that occur in many women with the disease. Spontaneous adenomyosis has been studied in nonhuman primates, primarily in the form of case reports. Adenomyosis is routinely experimentally induced in mice through methods such as neonatal tamoxifen exposure, pituitary engraftment, and human tissue xenotransplantation. Several studies have also reported hormonal or environmental toxicant exposures that give rise to murine adenomyosis, and genetically engineered models have been created that recapitulate the human-like condition, most notably involving alteration of β-catenin expression. This review describes the animal models for adenomyosis and their contributions to our understanding of the factors underpinning the development of symptoms. Animal models represent a unique opportunity for understanding the molecular basis of adenomyosis and developing efficacious treatment options for affected women. Herein, we assess their different potentials and limitations with regard to identification of new therapeutic interventions and reflect on future directions for research and drug validation.

Immunological changes associated with adenomyosis: a systematic review

BACKGROUND

Adenomyosis is a benign gynecological disorder associated with subfertility, pelvic pain and abnormal uterine bleeding that have significant consequences for the health and quality of life of women. Histologically, it is defined as the presence of ectopic endometrial islets within the myometrium. Its pathogenesis has not yet been elucidated and several pieces of the puzzle are still missing. One process involved in the development of adenomyosis is the increased capacity of some endometrial cells to infiltrate the myometrium. Moreover, the local and systemic immune systems are associated with the onset of the disease and with maintaining it. Numerous observations have highlighted the activation of immune cells and the release of immune soluble factors in adenomyosis. The contribution of immunity occurs in conjunction with hormonal aberrations and activation of the epithelial to mesenchymal transition (EMT) pathway, which promotes migration of endometrial cells. Here, we review current knowledge on the immunological changes in adenomyosis, with the aim of further elucidation of the pathogenesis of this disease.

OBJECTIVE AND RATIONALE

The objective was to systematically review the literature regarding the role of the immune system in development of adenomyosis in the inner and the outer myometrium, in humans.

SEARCH METHODS

A systematic review of published human studies was performed in MEDLINE, EMBASE and Cochrane Library databases from 1970 to February 2019 using the combination of Medical Subject Headings (MeSH): Adenomyosis AND ('Immune System' OR 'Gonadal Steroid Hormones'), and free-text terms for the following search terms (and their variants): Adenomyosis AND (immunity OR immune OR macrophage OR 'natural killer cell' OR lymphocyte* OR leucocyte* OR HLA OR inflammation OR 'sex steroid' OR 'epithelial to mesenchymal transition' OR 'EMT'). Studies in which no comparison was made with control patients, without adenomyosis (systemic sample and/or eutopic endometrium), were excluded.

OUTCOMES

A total of 42 articles were included in our systematic review. Changes in innate and adaptive immune cell numbers were described in the eutopic and/or ectopic endometrium of women with adenomyosis compared to disease-free counterparts. They mostly described an increase in lymphocyte and macrophage cell populations in adenomyosis eutopic endometrium compared to controls. These observations underscore the immune contributions to the disease pathogenesis. Thirty-one cytokines and other markers involved in immune pathways were studied in the included articles. Pro-inflammatory cytokines (interleukin (IL) 6, IL1β, interferon (IFN) α, tumor necrosis factor α, IFNγ) as well as anti-inflammatory or regulatory mediators (IL10, transforming growth factor β…) were found to be elevated in the eutopic endometrium and/or in the ectopic endometrium of the myometrium in women with adenomyosis compared to controls. Moreover, in women affected by adenomyosis, immunity was reported to be directly or indirectly linked to sex steroid hormone aberrations (notably changes in progesterone receptor in eutopic and ectopic endometrium) in three studies and to EMT in four studies.

WIDER IMPLICATIONS

The available literature clearly depicts immunological changes that are associated with adenomyosis. Both systemic and local immune changes have been described in women affected by adenomyosis, with the coexistence of changes in inflammatory as well as anti-inflammatory signals. It is likely that these immune changes, through an EMT mechanism, stimulate the migration of endometrial cells into the myometrium that, together with an endocrine imbalance, promote this inflammatory process. In light of the considerable impact of adenomyosis on women's health, a better understanding of the role played by the immune system in adenomyosis is likely to yield new research opportunities to better understand its pathogenesis.

Origin and Pathogenic Mechanisms of Uterine Adenomyosis: What Is Known So Far

Uterine adenomyosis is a benign disease, commonly encountered in reproductive-age women and responsible for chronic pelvic pain, abnormal uterine bleeding, and infertility. Although the exact origin and pathogenic mechanisms involved in adenomyosis still need to be elucidated, significant progress has been made over recent years. Ever since the theory of endometrium invaginating the myometrium via a traumatized interface was first proposed, numerous molecular mechanisms have been reported to participate in this process. At the same time, an alternative theory has suggested de novo development of adenomyotic lesions from metaplasia of Müllerian remnants or adult stem cells. Hence, our understanding of the pathogenesis of adenomyosis has been greatly enhanced and is anticipated to pave the way for development of an effective and safe treatment. The goal of this review is to analyze current knowledge on the origin and pathogenic mechanisms of adenomyosis, ranging from the most widely accepted theories to newly reported data.

Pathology and Pathogenesis of Adenomyosis

Adenomyosis represents a unique pathophysiological condition in which normal-appearing endometrial mucosa resides within myometrium and is thus protected from menstrual shedding. The resulting ectopic presence of endometrial tissue composed of glands and stroma is thought to affect normal contractile function and peristalsis of uterine smooth muscle, causing menometrorrhagia, infertility, and adverse obstetric outcomes. Since the first description of adenomyosis more than 150 years ago, pathologists have studied this lesion by examining tissue specimens, and have proposed multiple explanations to account for its pathogenesis. However, as compared with endometriosis, progress of adenomyosis research has been, at best, incremental mainly due to the lack of standardized protocols in sampling tissue and a lack of consensus diagnostic criteria in pathology practice. Despite these limitations, recent advances in revealing the detailed anatomy and biology of eutopic endometrium offer an unprecedented opportunity to study this common but relatively understudied disorder. Here, we briefly summarize the pathological aspects of adenomyosis from an historical background, and discuss conventional morphology and recent tissue-based molecular studies with a special emphasis on elucidating its tissue of origin from a pathologist's perspective. We also discuss unmet needs in pathology studies that would be important for advancing adenomyosis research.

β-catenin activates TGF-β-induced epithelial-mesenchymal transition in adenomyosis

Adenomyosis is defined as the presence of ectopic nests of endometrial glands and stroma within the myometrium. Adenomyosis is a common cause of dysmenorrhea, menorrhagia, and chronic pelvic pain but is often underdiagnosed. Despite its prevalence and severity of symptoms, its pathogenesis and etiology are poorly understood. Our previous study showed that aberrant activation of β-catenin results in adenomyosis through epithelial–mesenchymal transition. Using transcriptomic and ChIP-seq analysis, we identified activation of TGF-β signaling in the uteri of mutant mice that expressed dominant stabilized β-catenin in the uterus. There was a strong positive correlation between β-catenin and TGF-β2 proteins in women with adenomyosis. Furthermore, treatment with pirfenidone, a TGF-β inhibitor, increased E-cadherin expression and reduced cell invasiveness in Ishikawa cells with nuclear β-catenin. Our results suggest that β-catenin activates TGF-β-induced epithelial–mesenchymal transition in adenomyosis. This finding describes the molecular pathogenesis of adenomyosis and the use of TGF-β as a potential therapeutic target for adenomyosis.

A regulatory link between two proteins involved in the progression of a debilitating uterine condition highlights a potential therapeutic target. Adenomyosis involves the invasion of cells from the inner lining of the uterus (the endometrium) into the uterine muscle wall (the myometrium), resulting in heavy, prolonged periods and chronic pain. The aberrent activation of a protein called β-catenin triggers adenomyosis, but the precise mechanisms are unclear. A team led by Jung-Ho Shin at the Korea University Medical Center, Seoul, South Korea, and Jae-Wook Jeong, Michigan State University, Grand Rapids, USA, used sequencing techniques in mice and human tissue samples to identify the pathways governed by β-catenin in adenomyosis. They found that the Tgf-β2 gene is directly regulated by β-catenin in the uterus. TGF-β2 levels were elevated in human adenomyosis lesions, suggesting the protein could be a therapeutic target.

Adenomyosis: Mechanisms and Pathogenesis

Adenomyosis is a common disorder of the uterus, and is associated with an enlarged uterus, heavy menstrual bleeding (HMB), pelvic pain, and infertility. It is characterized by endometrial epithelial cells and stromal fibroblasts abnormally found in the myometrium where they elicit hyperplasia and hypertrophy of surrounding smooth muscle cells. While both the mechanistic processes and the pathogenesis of adenomyosis are uncertain, several theories have been put forward addressing how this disease develops. These include intrinsic or induced (1) microtrauma of the endometrial-myometrial interface; (2) enhanced invasion of endometrium into myometrium; (3) metaplasia of stem cells in myometrium; (4) infiltration of endometrial cells in retrograde menstrual effluent into the uterine wall from the serosal side; (5) induction of adenomyotic lesions by aberrant local steroid and pituitary hormones; and (6) abnormal uterine development in response to genetic and epigenetic modifications. Dysmenorrhea, HMB, and infertility are likely results of inflammation, neurogenesis, angiogenesis, and contractile abnormalities in the endometrial and myometrial components. Elucidating mechanisms underlying the pathogenesis of adenomyosis raise possibilities to develop targeted therapies to ameliorate symptoms beyond the current agents that are largely ineffective. Herein, we address these possible etiologies and data that support underlying mechanisms.

m6A RNA Methylation Regulators Contribute to Eutopic Endometrium and Myometrium Dysfunction in Adenomyosis

Adenomyosis is a prevalent, estrogen-dependent uterine disorder wherein endometrial cells are abnormally present in the myometrium and are surrounded by hyperplastic/hypertrophic smooth muscle. Its etiology is unclear, although endometrial cell invasion into the myometrium has been postulated. RNA methylation, particularly N6-methyladenosine (m6A), plays an important role in regulating various physiological processes and invasive disorders. The goal of this in silico and lab-based experimental study was to explore a possible role for m6A in adenomyosis. Gene expression profiles of both the endometrium and myometrium of women with adenomyosis (cases) and without disease (controls) were obtained from the publicly available Gene Expression Omnibus (GEO) database. In the endometrium, STRING database analysis revealed that METTL3 functions as a "hub" gene of m6A RNA methylation regulators, and the genes involved in m6A regulation, including METTL3, FTO, ZC3H13, and YTHDC1 expression, were significantly decreased in cases versus controls. Functional, co-expression, and correlational analyses of endometrium from cases versus controls revealed decreased total m6A levels, induced by METTL3, and the downstream elevated insulin-like growth factor-1(IGF1) and D-Dopachrome Tautomerase (DDT), with the latter two having known functions in epithelial proliferation and cell migration, which are important processes in the pathogenesis of adenomyosis in endometrium. m6A RNA methylation regulators, including RBM15/15B, ALKBH5, FTO, YTHDF1/2, KIAA1429, HNRNPC, METTL3, ZC3H13, and YTHDC2, were also differentially expressed in the myometrium from cases versus controls. We validated decreased total m6A levels and differential expression of m6A RNA methylation regulators in the myometrium of patients with adenomyosis using qRT-PCR, immunohistochemistry and tissues available from our biorepository. Possible target genes, including cadherin 3(CDH3), sodium channelβ-subunit 4 (SCN4B), and placenta-specific protein 8 (PLAC8), which are involved in cell adhesion, muscle contraction and immune response in the myometrium of adenomyosis patients were also validated. Thus, through extensive public database mining and validation of select genes, this study, for the first time, implicates m6A and its methylation regulators in the pathogenesis of adenomyosis. Follow on functional studies are anticipated to elucidate mechanisms involving m6A and its regulators and down-stream effectors in the pathogenesis of this enigmatic reproductive disorder and potentially identify druggable targets to control its associated symptoms.

Rapid Effects of Oestrogen on Intracellular Ca2+ in the Uterine Junctional Myometrium of Patients With and Without Adenomyosis in Different Phases of the Menstrual Cycle

We investigated the role of oestrogen receptor 1 (ESR1) in regulating the [Ca²⁺]i concentration in the junctional zone (JZ) and its effect on adenomyosis. JZ smooth muscle cells (JZSMCs) were isolated from 17 control and 24 adenomyotic uteri, and membrane proteins were extracted from the cells. In the control group, the levels of membrane ESR1 and [Ca²⁺]i in the proliferative phase were significantly greater than they were in the secretory phase. While no difference was detected between the two phases, ESR1 and [Ca²⁺]i levels in the adenomyosis group were significantly higher in the proliferative and secretory phases than they were in the control groups. Oestradiol induced a rapid increase in [Ca²⁺]i in the JZSMCs of both groups. When pretreated with the ESR1 antagonist ICI 182,780, the increase in [Ca²⁺]i was clearly reduced in both groups compared with the control, but the differences were not significant. Filtered E-6-BSA also induced [Ca²⁺]i, and its actions were similar to those of oestrogen. Removal of extracellular Ca²⁺ did not alter the effect of oestradiol, but the phospholipase C inhibitor U73122 (10 μM) and 2-aminoethoxydiphenyl borate (5 μM) significantly reduced the oestradiol-induced [Ca²⁺]i flux. Oestradiol was unable to induce a [Ca²⁺]i flux in thapsigargin-depleted cells; this result indicated that oestradiol mediates the [Ca²⁺]i flux in JZSMCs through ESR1, which activates the phospholipase C pathway. ESR1 levels were assessed by Western blotting. Changes in the [Ca²⁺]i concentration induced by oestrogen stimulation were analysed by immunofluorescence. The ΔFCa²⁺ was calculated as the difference between baseline and peak fluorescence response to stimulation. We found that the abnormal intracellular [Ca²⁺]i response to oestrogen could account for aberrant JZ peristalsis.