Pathogenesis of adenomyosis: an update on molecular mechanisms

Hormonal treatments for endometriosis: The endocrine background

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

Epigenomic Analysis Reveals the KCNK9 Potassium Channel as a Potential Therapeutic Target for Adenomyosis

Adenomyosis is linked to dysmenorrhea and infertility. The pathogenesis of adenomyosis remains unclear, and little is known of the genetic and epigenetic changes in the eutopic endometrium in adenomyosis, which may predispose patients to the invasion and migration of endometrial tissues into the myometrium. Transcriptome studies have identified genes related to various cell behaviors but no targets for therapeutic intervention. The epigenetics of the eutopic endometrium in adenomyosis have rarely been investigated. Endometrial tissue was obtained from premenopausal women with (n = 32) or without adenomyosis (n = 17) who underwent hysterectomy aged 34–57 years at a tertiary hospital. The methylome and transcriptome were assessed by using a Methylation 450 K BeadChip array and Affymetrix expression microarray. Protein expression was examined by immunohistochemistry. Differential methylation analysis revealed 53 lowly methylated genes and 176 highly methylated genes with consistent gene expression in adenomyosis, including three genes encoding potassium ion channels. High expression of KCNK9 in the eutopic and ectopic endometria in patients with adenomyosis but not in normal controls was observed. Hormone-free, antibody-based KCNK9 targeting is a potential therapeutic strategy for adenomyosis-related dysmenorrhea, menorrhagia, and infertility.

Perioperative Suppression of Schwann Cell Dedifferentiation Reduces the Risk of Adenomyosis Resulting from Endometrial–Myometrial Interface Disruption in Mice

We have recently demonstrated that endometrial–myometrial interface (EMI) disruption (EMID) can cause adenomyosis in mice, providing experimental evidence for the well-documented epidemiological finding that iatrogenic uterine procedures increase the risk of adenomyosis. To further elucidate its underlying mechanisms, we designed this study to test the hypothesis that Schwann cells (SCs) dedifferentiating after EMID facilitate the genesis of adenomyosis, but the suppression of SC dedifferentiation perioperatively reduces the risk. We treated mice perioperatively with either mitogen-activated protein kinase kinase (MEK)/extracellular-signal regulated protein kinase (ERK) or c-Jun N-terminal kinase (JNK) inhibitors or a vehicle 4 h before and 24 h, 48 h and 72 h after the EMID procedure. We found that EMID resulted in progressive SCs dedifferentiation, concomitant with an increased abundance of epithelial cells in the myometrium and a subsequent epithelial–mesenchymal transition (EMT). This EMID-induced change was abrogated significantly with perioperative administration of JNK or MEK/ERK inhibitors. Consistently, perioperative administration of a JNK or a MEK/ERK inhibitor reduced the incidence by nearly 33.5% and 14.3%, respectively, in conjunction with reduced myometrial infiltration of adenomyosis and alleviation of adenomyosis-associated hyperalgesia. Both treatments significantly decelerated the establishment of adenomyosis and progression of EMT, fibroblast-to-myofibroblast trans-differentiation and fibrogenesis in adenomyotic lesions. Thus, we provide the first piece of evidence strongly implicating the involvement of SCs in the pathogenesis of adenomyosis induced by EMID.

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.

Adenomyosis is an independent risk factor for complications in deep endometriosis laparoscopic surgery

Deep endometriosis (DE) occurs in 15-30% of patients with endometriosis and is associated with concomitant adenomyosis in around 25-49% of cases. There are no data about the effect of the presence of adenomyosis in terms of surgical outcomes and complications. Thus, the aim of the present study was to evaluate the impact of adenomyosis on surgical complications in women with deep endometriosis undergoing laparoscopic surgery. A retrospective cohort study including women referred to the endometriosis unit of a referral teaching hospital. Two expert sonographers preoperatively diagnosed DE and adenomyosis. DE was defined according to the criteria of the International Deep Endometriosis Analysis group. Adenomyosis was considered when 3 or more ultrasound criteria of the Morphological Uterus Sonographic Assessment group were present. Demographical variables, current medical treatment, symptoms, DE location, surgical time, hospital stay and difference in pre and post hemoglobin levels were collected. The Clavien-Dindo classification was used to assess surgical complications, and multivariate analysis was performed to compare patients with and without adenomyosis. 157 DE patients were included into the study; 77 (49.05%) had adenomyosis according to transvaginal ultrasound (TVS) and were classified in the A group, and 80 (50.95%) had no adenomyosis and were classified in the noA group. Adenomyosis was associated with a higher rate of surgical complications: 33.76% (A group) vs. 12.50% (noA group) (p < 0.001). Multivariate analysis showed a 4.56-fold increased risk of presenting complications in women with adenomyosis (CI 1.90-11.30; p = 0.001) independently of undergoing hysterectomy. There was a statistically significant association between the number of criteria of adenomyosis present in each patient and the proportion of patients presenting surgical complications (p < 0.001). Adenomyosis is an independent preoperative risk factor for surgical complications in DE surgery after adjustment for known demographic, clinical and surgical risk factors.

Unveiling the Pathogenesis of Adenomyosis through Animal Models

Background: Adenomyosis is a common gynecological disorder traditionally viewed as “elusive”. Several excellent review papers have been published fairly recently on its pathogenesis, and several theories have been proposed. However, the falsifiability, explanatory power, and predictivity of these theories are often overlooked. Since adenomyosis can occur spontaneously in rodents and many other species, the animal models may help us unveil the pathogenesis of adenomyosis. This review critically tallies experimentally induced models published so far, with a particular focus on their relevance to epidemiological findings, their possible mechanisms of action, and their explanatory and predictive power. Methods: PubMed was exhaustively searched using the phrase “adenomyosis and animal model”, “adenomyosis and experimental model”, “adenomyosis and mouse”, and “adenomyosis and rat”, and the resultant papers were retrieved, carefully read, and the resultant information distilled. All the retrieved papers were then reviewed in a narrative manner. Results: Among all published animal models of adenomyosis, the mouse model of adenomyosis induced by endometrial–myometrial interface disruption (EMID) seems to satisfy the requirements of falsifiability and has the predictive capability and also Hill’s causality criteria. Other theories only partially satisfy Hill’s criteria of causality. In particular, animal models of adenomyosis induced by hyperestrogenism, hyperprolactinemia, or long-term exposure to progestogens without much epidemiological documentation and adenomyosis is usually not the exclusive uterine pathology consequent to those induction procedures. Regardless, uterine disruption appears to be a necessary but not sufficient condition for causing adenomyosis. Conclusions: EMID is, however, unlikely the sole cause for adenomyosis. Future studies, including animal studies, are warranted to understand how and why in utero and/or prenatal exposure to elevated levels of estrogen or estrogenic compounds increases the risk of developing adenomyosis in adulthood, to elucidate whether prolactin plays any role in its pathogenesis, and to identify sufficient condition(s) that cause adenomyosis.

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).

Integrative metabolomic profiling reveals aberrations in myometrium associated with adenomyosis: a pilot study

BACKGROUND

Uterine adenomyosis is a common gynecologic disease in premenopausal women, the pathological mechanism of which remains largely unknown. The aim of this study was to identify metabolic biomarkers significantly altered in the myometrium of adenomyosis patients.

METHODS

The comprehensive metabolomic profiles of 17 myometrium specimens from adenomyosis patients and 25 control specimens were analyzed using untargeted approach by combination of gas chromatography-mass spectrometry and high performance liquid chromatography-mass spectrometry. Metabolic data were filtered using orthogonal partial least square-discriminant analysis and univariate statistics.

RESULTS

We firstly demonstrated that the myometrial metabolome of women with adenomyosis is distinct from that of women without adenomyosis. A total of 106 metabolites, mainly including nucleosides, lipids (including acylcarnitines), amino acids, organic acids and carbohydrates, were found to be differentially expressed in myometrium of uteri with adenomyosis compared to the control subjects. Functional inferences of these perturbed metabolites indicated that inflammation, oxidative stress, cell proliferation and apoptosis, and energy metabolism appeared to be involved in the progress of adenomyosis.

CONCLUSION

This study firstly described the integrated metabolic signatures of the adenomyosis uterus, which provided novel insights for the pathogenesis study of this disease.

Vaginal microbiome of women with adenomyosis: A case-control study

Immune dysregulation can involve invasion and survival of endometrial glands inside the myometrium of the adenomyosis. There is limited available data concerning alterations of the bacterial microbiome in the reproductive tract of adenomyosis women. The present cross-sectional age-matched study aims to compare vaginal microbiota between women with and without adenomyosis. We recruited women with adenomyosis (N = 40) and age-matched women without adenomyosis (N = 40) from the Departments of Obstetrics and Gynaecology, Ramathibodi Hospital Mahidol University, from August 2020 to January 2021. Vaginal swab samples were collected from the participants. DNA isolation and bacterial 16s rDNA gene sequencing and data analyses were then performed. Comparison of the diversity of vaginal microbiota, microbiota composition, and the operational taxonomic unit (OTU) between adenomyosis and non-adenomyosis (control) groups were undertaken. Data from 40 and 38 women with and without adenomyosis, respectively, were analyzed. Alpha-diversity analysis (Chao1 index) at the species level showed higher vaginal microbial richness in the adenomyosis group when compared with the control group (p = 0.006). The linear discriminant analysis effect size technique (LeFSe) indicated an elevated abundance of several vaginal microbial taxa in the adenomyosis group, including Alloscardovia, Oscillospirales, Ruminoccoccaceae, UCG_002, Oscillospiraceae, Enhydrobacter, Megamonas, Moraxellaceae, Subdoligranulum, Selenomonadaceae, and Faecalibacterium. On the other hand, an increase in the abundance of Megaspehera, Fastidiosipila, Hungateiclostridiaceae, and Clostridia was identified in the control group. Vaginal community state type (CST)-III and -IV were dominated in adenomyosis, while only CST-IV was dominated in the non-adenomyosis group. Lactobacillus was the most abundant vaginal microbial in both groups. In this study, the differences in vaginal microbiome profile were noted between adenomyosis and non-adenomyosis group. The increasing of microbial richness was associated with adenomyosis. Nevertheless, further investigations were required to elucidate the mechanisms and apply them for clinical implications.

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.

Menstruation-Related Disorders—Dysmenorrhea and Heavy Bleeding—as Significant Epiphenomena in Women With Rheumatic Diseases

Background: In women with rheumatic diseases (RDs) menstruation-related disorders have never been investigated. The aim of this study was to evaluate gynecological symptoms/disorders in fertile age women with RDs.

Materials and methods: All patients (n = 200) filled up a self-administered questionnaire on their gynecological history, menstrual cycle pattern, menstrual-related symptoms, and quality of life (QoL). The RD group was then compared to a control group of 305 age-matched fertile age women.

Results: Among patients with RDs, 58% had arthritis, 40% connective tissue diseases (CTDs), and 1.5% systemic vasculitis. No differences were observed between CTDs and arthritis, except for a family history of HMB which was more common among women with CTDs (p < .01). When compared to controls, women with RDs reported more frequent heavy menstrual bleeding (HMB) during adolescence (51.7 and 25.4%, respectively; p = .0001) and adult life (37.7 and 25.9%, respectively; p = .0065). Also, dysmenorrhea in adolescence was significantly more common among cases (55.6 and 45.4%, respectively; p = .0338). Gynecological pain (dysmenorrhea, non-menstrual pelvic pain, dyspareunia, dysuria, and dyschezia) in patients with RDs was more frequent than in controls (p = .0001, .0001, .0001, .0001, .0002, respectively). Considering women who reported moderate and severe symptoms in RDs, dysmenorrhea and dyspareunia remain significantly more frequent in women with RDs than in controls (p = .0001; p = .0022; respectively). QoL scores were significantly reduced in women with RDs, either in physical (p = .0001) and mental domains (p = .0014) of short-form 12.

Conclusion: Women affected by RDs frequently presented menstruation-related disorders; thus, female patients with RDs should be questioned about gynecological symptoms and referred to the gynecologist for an accurate evaluation.

The Potential Relationship Between Environmental Endocrine Disruptor Exposure and the Development of Endometriosis and Adenomyosis

Women with endometriosis, the growth of endometrial glands and stroma outside the uterus, commonly also exhibit adenomyosis, the growth of endometrial tissues within the uterine muscle. Each disease is associated with functional alterations in the eutopic endometrium frequently leading to pain, reduced fertility, and an increased risk of adverse pregnancy outcomes. Although the precise etiology of either disease is poorly understood, evidence suggests that the presence of endometriosis may be a contributing factor to the subsequent development of adenomyosis as a consequence of an altered, systemic inflammatory response. Herein, we will discuss the potential role of exposure to environmental toxicants with endocrine disrupting capabilities in the pathogenesis of both endometriosis and adenomyosis. Numerous epidemiology and experimental studies support a role for environmental endocrine disrupting chemicals (EDCs) in the development of endometriosis; however, only a few studies have examined the potential relationship between toxicant exposures and the risk of adenomyosis. Nevertheless, since women with endometriosis are also frequently found to have adenomyosis, discussion of EDC exposure and development of each of these diseases is relevant. We will discuss the potential mechanisms by which EDCs may act to promote the co-development of endometriosis and adenomyosis. Understanding the disease-promoting mechanisms of environmental toxicants related to endometriosis and adenomyosis is paramount to designing more effective treatment(s) and preventative strategies.

Parallel targeted and non-targeted quantitative analysis of steroids in human serum and peritoneal fluid by liquid chromatography high-resolution mass spectrometry

We developed and validated a liquid chromatography high-resolution mass spectrometry method for the absolute quantification of 51 steroids for clinical analysis of human serum and, for the first time, peritoneal fluid. Data acquisition was performed in both targeted and untargeted mode simultaneously, thus allowing the accurate and precise quantification of the main components of the classical steroid pathways (17 steroids) as well as the analysis of 34 additional non-classical steroids. For targeted analysis, validation was performed according to FDA guidelines, resulting, among other parameters, in accuracy < 13% RSD and precision < 10% relative error, for both inter- and intra-day validation runs. By establishing steroid-specific response factors, the calibration curves of the targeted analytes can be extended to untargeted analytes. This approach opens novel possibilities for the post hoc analysis of clinical samples as the data can be examined for virtually any steroid even after data acquisition, enabling facile absolute quantification once a standard becomes available. We demonstrate the applicability of the approach to evaluate the differences in steroid content between peripheral serum and peritoneal fluid across the menstrual cycle phases, as well as the effect of the synthetic gestagen dienogest on the steroid metabolome.

Evaluation of pharmacological interventions in the management of adenomyosis: a systematic review

PURPOSE

Medical management of adenomyosis largely revolves around symptom management, with very few drugs having received regulatory approval for the disease. However, the level of evidence supporting the use of pharmacological interventions is low, making it difficult to establish their efficacy in the treatment of adenomyosis. Hence, the aim of our systematic review is to identify the strength of evidence currently available and evaluate the effectiveness of different medical interventions in the management of adenomyosis.

METHODS

The search was performed in MEDLINE, Embase, Cochrane Library, CENTRAL and ClinicalTrials.gov. Articles published between 1 January 2010 and 30 November 2020 were considered. Randomized controlled trials and observational studies that assessed the efficacy of medical interventions in patients with adenomyosis were included. The quality of the data was analyzed using RevMan 5.3 software.

RESULTS

LNG-IUS (levonorgestrel intrauterine system), dienogest and gonadotropin-releasing hormone (GnRH) analogues were effective in reducing pain, uterine volume and menstrual bleeding. However, these data were largely obtained in the non-trial setting and were fraught with issues that included patient selection, short duration of therapy, small sample size, and limited long-term safety and effectiveness data.

CONCLUSIONS

Although LNG-IUS, dienogest and GnRH analogues have better evidence for effectiveness in adenomyosis, the need of the hour is to thoroughly evaluate other novel molecules for adenomyosis using well-designed randomized controlled trials.

Iron overload inhibits cell proliferation and promotes autophagy via PARP1/SIRT1 signaling in endometriosis and adenomyosis

Emerging evidence suggests that excess iron accumulates in endometriotic and adenomyotic lesions. However, the role iron overload plays in the pathogenesis of endometriosis or adenomyosis remains unknown. Primary human eutopic endometrial stromal cells (EuESCs) from endometriosis or adenomyosis patients were used as the in vitro model of endometriosis or adenomyosis in this study. We found that iron, manifesting as ferric ammonium citrate (FAC; 0.05-4.8 mM), significantly inhibited cell growth, induced oxidative stress through the Fenton reaction, and functionally activated autophagy in EuESCs, as measured by 5-ethynyl-2'-deoxyuridine incorporation assay, MitoSOX™ Red staining, LC3 turnover assay, and tandem mCherry-eGFP-LC3B fluorescence microscopy. Immunohistochemistry analysis of Ki67 expression in proliferative-phase endometrial tissues revealed that cell proliferation in ectopic tissues was dramatically compromised, suggesting that iron overload may play a role in cell growth inhibition in vivo. We observed that autophagy may alleviate the FAC-induced inhibition of endometrial stromal cell proliferation. Furthermore, sequential FAC (0.8 mM, 24 h) and hydrogen peroxide (H₂O₂; 300 μM, 2 h) treatment successfully induced the Fenton reaction in EuESCs and caused extensive apoptosis, whereas the disruption of autophagy by the knockdown of BECN1 further aggravated cell death. MitoSOX™ Red staining showed that autophagy may promote the survival of EuESCs by decreasing of the Fenton reaction-induced reactive oxygen species generation. In addition, we observed that the Fenton reaction-induced oxidative stress significantly suppressed iron overload-induced autophagy. Moreover, we found that FAC treatment impaired poly(ADP-ribose)-polymerase 1 (PARP1) expression while simultaneously upregulating SIRT1 expression in EuESCs. Our data further showed that PARP1 expression decreased in endometriotic lesions, which may partially result from iron overload. We also found that PARP1 inhibition aggravated iron overload-induced cell growth suppression, and was implicated in iron overload-induced autophagy. In addition, SIRT1 silencing alleviated iron overload-induced PARP1 downregulation and autophagy activation. Overall, our data suggest that iron overload in endometrial stromal cells of endometriotic or adenomyotic lesions may be involved in the inhibition of cell proliferation, simultaneously with the activation of protective autophagy via PARP1/SIRT1 signaling.

Increased risk of obstetric complications in patients with adenomyosis: A narrative literature review

Background

Reproductive‐age women occasionally face the pathological condition of adenomyosis, which is often concurrent with endometriosis. It is believed that endometriosis and adenomyosis increases the risk of obstetric complications. Although new insights into the mechanism of obstetric complications due to endometriosis are emerging, there is little information on the etiology of adverse pregnancy outcomes in pregnant women with adenomyosis.

Methods

We performed a literature review focusing on the pathophysiological pathways of obstetric complications in women with adenomyosis using currently available basic and clinical studies. We used the internet search engines PubMed and Google Scholar to search for studies published between January 2000 and June 2021. We carefully read pertinent sections within each document to ensure relevancy.

Main findings

The prevalence of adverse pregnancy outcomes in women with adenomyosis is increased after adjusting for conceiving by assisted reproductive technology. Thus, adenomyosis emerges as a relevant factor associated with several obstetric complications such as preterm birth, preterm premature rupture of membranes, placental abruption, small for gestational age/fetal growth restriction, and preeclampsia.

Conclusion

It is plausible that the impact of adenomyosis on pregnancy outcomes is not always the same; rather it is dependent on the degree of uterine involvement and subtypes.

Efficacy and safety of acupuncture for adenomyosis: A protocol for systematic review and meta-analysis

BACKGROUND

Adenomyosis (AM) is a disease in which the endometrium (including glands and stroma) invades the myometrium and grows. The main clinical symptoms include menorrhagia, dysmenorrhea, chronic pelvic pain, metrorrhagia, and dyspareunia, which will seriously affect the physical and mental health of patients, and most of which occur in women of childbearing age. Acupuncture, as a special external treatment of Traditional Chinese medicine, has shown good effects in the treatment of adenomyosis. At present, there is a lack of systematic review on acupuncture in the treatment of adenomyosis. We conduct this study to evaluate the efficacy and safety of acupuncture in the treatment of adenomyosis.

METHODS

We will search Chinese and English databases: Medline, Pubmed, EMBASE, Cochrane library, China National Knowledge Infrastructure (CNKI), Chinese Scientific and Journal Database, Wan Fang database (Wanfang), Chinese Biomedical Literature Database (CBM) to identify articles of randomized clinical trials of acupuncture for adenomyosis. All above electronic databases will be searched from inception to September 30, 2021. RevMan 5.3 software will be used to conduct this systematic review. No language and publication status restrictions will be applied.

RESULTS

The study will prove the efficacy and safety of acupuncture for adenomyosis.

CONCLUSION

We plan to submit this systematic review to a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

CRD42021277136.

Novel microarchitecture of human endometrial glands: implications in endometrial regeneration and pathologies

BACKGROUND

Human endometrium remains a poorly understood tissue of the female reproductive tract. The superficial endometrial functionalis, the site of embryo implantation, is repeatedly shed with menstruation, and the stem cell-rich deeper basalis is postulated to be responsible for the regeneration of the functionalis. Two recent manuscripts have demonstrated the 3D architecture of endometrial glands. These manuscripts have challenged and replaced the prevailing concept that these glands end in blind pouches in the basalis layer that contain stem cells in crypts, as in the intestinal mucosa, providing a new paradigm for endometrial glandular anatomy. This necessitates re-evaluation of the available evidence on human endometrial regeneration in both health and disease in the context of this previously unknown endometrial glandular arrangement.

OBJECTIVE AND RATIONALE

The aim of this review is to determine if the recently discovered glandular arrangement provides plausible explanations for previously unanswered questions related to human endometrial biology. Specifically, it will focus on re-appraising the theories related to endometrial regeneration, location of stem/progenitor cells and endometrial pathologies in the context of this recently unravelled endometrial glandular organization.

SEARCH METHODS

An extensive literature search was conducted from inception to April 2021 using multiple databases, including PubMed/Web of Science/EMBASE/Scopus, to select studies using keywords applied to endometrial glandular anatomy and regeneration, and the references included in selected publications were also screened. All relevant publications were included.

OUTCOMES

The human endometrial glands have a unique and complex architecture; branched basalis glands proceed in a horizontal course adjacent to the myometrium, as opposed to the non-branching, vertically coiled functionalis glands, which run parallel to each other as is observed in intestinal crypts. This complex network of mycelium-like, interconnected basalis glands is demonstrated to contain endometrial epithelial stem cells giving rise to single, non-branching functionalis glands. Several previous studies that have tried to confirm the existence of epithelial stem cells have used methodologies that prevent sampling of the stem cell-rich basalis. More recent findings have provided insight into the efficient regeneration of the human endometrium, which is preferentially evolved in humans and menstruating upper-order primates.

WIDER IMPLICATIONS

The unique physiological organization of the human endometrial glandular element, its relevance to stem cell activity and scarless endometrial regeneration will inform reproductive biologists and clinicians to direct their future research to determine disease-specific alterations in glandular anatomy in a variety of endometrial pathological conditions.

Mode Switch of Ca2 + Oscillation-Mediated Uterine Peristalsis and Associated Embryo Implantation Impairments in Mouse Adenomyosis

Adenomyosis is a debilitating gynecological disease of the uterus with no medicinal cure. The tissue injury and repair hypothesis for adenomyosis suggests that uterine hyperperistalsis or dysperistalsis plays a pivotal role in establishing adenomyotic lesions. However, specific impairments in uterine peristalsis and the underlying cellular signals for these changes in adenomyosis remain elusive. Here, we report a precision-cut uterine slice preparation that preserves in vivo uterine architecture and generates peristalsis similar to that seen in the whole uterus. We found that uterine peristalsis in neonatal mice at day 14 and adult mice at day 55 presents as bursts with multiple peaks induced by intracellular Ca²⁺ oscillations. Using a mouse model of adenomyosis induced by tamoxifen, a selective estrogen receptor modulator, we discovered that uterine peristalsis and Ca²⁺ oscillations from adenomyotic uteri on days 14 and 55 become spikes (single peaks) with smaller amplitudes. The peak frequency of Ca²⁺ oscillations or peristalsis does not show a difference between control and adenomyotic mice. However, both the estimated force generated by uterine peristalsis and the total Ca²⁺ raised by Ca²⁺ oscillations are smaller in uteri from adenomyotic mice. Uteri from adenomyotic mice on day 14, but not on day 55, exhibit hyperresponsiveness to oxytocin. Embryo implantations are decreased in adenomyotic adult mice. Our results reveal a mode switch from bursts to spikes (rather than an increased peak frequency) of uterine Ca²⁺ oscillations and peristalsis and concurrent hyperresponsiveness to oxytocin in the neonatal stage are two characteristics of adenomyosis. These characteristics may contribute to embryo implantation impairments and decreased fertility in adenomyosis.

International Harmonization of Nomenclature and Diagnostic Criteria (INHAND): Non-proliferative and Proliferative Lesions of the Non-human Primate (M. fascicularis)

The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions Project (www.toxpath.org/inhand.asp) is a joint initiative of the Societies of Toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying microscopic lesions observed in most tissues and organs from the nonhuman primate used in nonclinical safety studies. Some of the lesions are illustrated by color photomicrographs. The standardized nomenclature presented in this document is also available electronically on the internet (http://www.goreni.org/). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous lesions as well as lesions induced by exposure to test materials. Relevant infectious and parasitic lesions are included as well. A widely accepted and utilized international harmonization of nomenclature for lesions in laboratory animals will provide a common language among regulatory and scientific research organizations in different countries and increase and enrich international exchanges of information among toxicologists and pathologists.

Effectiveness of modified downregulation for women with moderate and severe adenomyosis of the uterus prior to frozen thawed embryo transfer (MODA) study protocol: a pragmatic randomised-controlled trial

INTRODUCTION

Adenomyosis can adversely reduce chances of pregnancy in couples undergoing assisted conception. We aim to evaluate the effect of two different downregulation protocols on the reproductive outcomes in women with moderate and severe adenomyosis undergoing frozen-thawed embryo transfer (FTET).

METHODS AND ANALYSIS

We will conduct a two-armed pragmatic randomised clinical trial comparing modified downregulation with gonadotrophin-releasing hormone (GnRH) analogue for 6 weeks to standard downregulation with GnRH analogue for 1 week prior to FTET. Our primary outcome is clinical pregnancy, defined as a viable intrauterine pregnancy confirmed by ultrasound at greater than 6 weeks gestation, with other secondary reproductive, neonatal and safety outcomes. We aim to randomise 162 patients over 3 years to achieve 80% power for detecting a 20% difference in the primary outcome at 5% significance.

ETHICS AND DISSEMINATION

To date there is no consensus on the optimal protocol for management of subfertile women with adenomyosis. Modified downregulation could improve the clinical pregnancy rate by reducing the endometrial inflammatory reaction and/or myometrial contractility and their impact on uterine receptivity in women with moderate and severe adenomyosis of the uterus undergoing FTET. The MODA trial is designed to offer pragmatic, real-life evaluation of the optimal protocol for downregulation for this population during assisted conception treatments. Our findings will be published in peer-reviewed journals and presented at national and international scientific meetings and congresses. Ethical approval was granted by the NHS Research Ethics Committees (19/LO/1567).

TRIAL REGISTRATION NUMBER

NCT03946722.

Long-term GnRH agonist pretreatment before frozen embryo transfer improves pregnancy outcomes in women with adenomyosis

RESEARCH QUESTION

Do frozen embryo transfer (FET) cycles following long-term gonadotrophin-releasing hormone agonist (GnRHa) pretreatment have better pregnancy outcomes than fresh embryo transfer cycles with long or ultra-long GnRHa protocol in these patients?

DESIGN

This study included 537 women with adenomyosis divided into three groups: (Group A) FET cycles following long-term GnRHa pretreatment (192 patients); (Group B) fresh embryo transfer cycles with the ultra-long GnRHa protocol (241 patients); (Group C) fresh embryo transfer cycles with the long GnRHa protocol (104 patients).

RESULTS

The total gonadotrophin dose and stimulation duration were significantly lower in Group A than in Groups B and C. The implantation and live birth rates were significantly higher in Group A than in Groups B and C. In the long-term GnRHa pretreatment and FET treatment of Group A, implantation (odds ratio [OR] 1.729, 95% confidence interval [CI] 1.073-2.788, P = 0.025), clinical pregnancy (OR 1.665, 95% CI 1.032-2.686, P = 0.037) and live birth rates (OR 1.694, 95% CI 1.045-2.746, P = 0.033) increased and miscarriage rate (OR 0.203, 95% CI 0.078-0.530, P = 0.001) decreased when compared with Group C. Comparison of Groups A and B showed that with the long-term GnRHa pretreatment, FET was a protective factor for live birth rate (OR 1.350, 95% CI 1.017-1.792, P = 0.038).

CONCLUSION

FET following long-term GnRHa pretreatment has a better IVF/intracytoplasmic sperm injection outcome, and a potential benefit in terms of a lower gonadotrophin dose, and a shorter stimulation duration than fresh embryo transfer combined with a long or ultra-long GnRHa protocol.

[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.

The expression of BECN1, LC3B, and BCL2 genes in eutopic endometrium of patients with adenomyosis: A cross-sectional study

Introduction:

Both autophagy and apoptosis play a role in the cyclic remodeling of the endometrium. The abnormal regulation of genes and signaling pathways in the eutopic endometrium plays a role in the abnormal migration and implantation in adenomyosis.

Objective:

The present study investigates the mRNA expression of autophagy and apoptosis-related genes BECN1, LC3B, and BCL2 in the eutopic endometrium of patients with adenomyosis compared with healthy premenopausal women.

Materials and methods:

The present work was a cross-sectional study conducted between July 2018 and April 2019. The participants were 32 premenopausal women who attended the surgery for adenomyosis and other benign gynecological conditions. The participants were divided into two groups, with 16 women in the adenomyosis group and 16 healthy women in the control group. Endometrial tissues were collected during the proliferative menstrual phase for a quantitative real-time polymerase chain reaction.

Results:

The mRNA expression of BECN1, LC3B, and BCL2 were normalized by geometric mean mRNA expression of actin and GAPDH. There was no significant difference in mRNA expression for all three genes when comparing the control and adenomyosis groups.

Conclusions:

The mRNA expressions of autophagy-related genes BECN1 and LC3B and anti-apoptosis-related gene BCL2 were not significantly different in the eutopic endometrium of patients with adenomyosis compared with healthy premenopausal women during the proliferative menstrual phase.

Endometrial Cancer Incidence in Endometriosis and Adenomyosis

Women with histologically proven endometriosis/adenomyosis have an increased risk of ovarian cancer. Small studies show conflicting results on the endometrial cancer risk in women with endometriosis/adenomyosis. Therefore, we assessed the incidence of endometrial cancer in women with histologically proven endometriosis or adenomyosis. We performed a population-based retrospective cohort study of 129,862 women with histologically proven endometriosis/adenomyosis, matched with 132,700 women with a nevus selected from the Dutch pathology registry between 1990 and 2015. Histology results for endometrial cancer were retrieved. Crude and age-adjusted odds ratios for endometrial cancer were estimated. In the endometriosis/adenomyosis group, 1827 (1.4%) women had a histological report on endometrial cancer, and in the nevus group, 771 (0.6%) women. The age-adjusted OR for endometrial cancer was 2.58 (95%CI 2.37-2.81). After excluding the first year of follow-up, the age-adjusted OR was 0.76 (95%CI 0.63-0.92), indicating that endometrial cancer is most often found at time of histological diagnosis of endometriosis/adenomyosis. In around 20% of the endometrial cancer cases, the endometrial cancer was not recognized until after hysterectomy. Of these women, 35% had no prior (micro)curettage or biopsy. This study shows an increased incidence of endometrial cancer in women with histologically proven endometriosis and adenomyosis.

Efficacy of High-Intensity Focused Ultrasound Combined With GnRH-a for Adenomyosis: A Systematic Review and Meta-Analysis

Objective: High-intensity focused ultrasound (HIFU) is an innovative non-invasive technology used for adenomyosis. Gonadotropin-releasing hormone agonist (GnRH-a) is a hormone commonly used for adenomyosis. We investigated and assessed the efficacy of HIFU combined with GnRH-a for adenomyosis. Methods: For this systematic review and meta-analysis, we searched Pubmed, Cochrane Library, Web of Science, Embase, CNKI, WanFang, and VIP databases for relevant articles published in Chinese or English that compared HIFU combined with GnRH-a vs. HIFU alone in patients with adenomyosis. The last literature search was completed on January 31, 2021. Two reviewers independently assessed study eligibility and assessed risk of bias. Another two reviewers extracted the data. The RevMan5.3 software was used for the data analysis. Changes in volume of the uterine and adenomyotic lesion were defined as the primary outcomes. The secondary outcomes were visual analog scale (VAS) scores for dysmenorrhea, menstrual volume scores, serum CA125 levels, and recurrence rate. This study is registered with PROSPERO (CRD42021234301). Results: Three hundred and ninety potentially relevant articles were screened. Nine studies with data for 766 patients were finally included. Compared with the HIFU alone group, the HIFU combined with GnRH-a group had a higher rate of uterine volume reduction (MD 7.51, 95% CI 5.84-9.17, p < 0.00001), smaller adenomyotic lesion volume (MD 4.11, 95% CI 2.93-5.30, p < 0.00001), lower VAS score for dysmenorrhea (MD 1.27, 95% CI 0.54-2.01, p = 0.0007) and menstrual volume score (MD 0.88, 95% CI 0.73-1.04, p < 0.00001), and lower CA125 level (SMD 0.31, 95% CI 0.05-0.56, p = 0.02) after the procedure. The recurrence rate in the HIFU combined with GnRH-a group was lower than that in the HIFU alone group (RR 0.28, 95% CI 0.10-0.82, p = 0.02). Conclusions: Compared with HIFU treatment alone, HIFU combined with GnRH-a for the treatment of adenomyosis has greater efficacy in decreasing the volumes of the uterine and adenomyotic lesions and alleviating symptoms. However, since the number of the included studies was too small and most of them were written in Chinese, this conclusion needs to be referenced with caution. And the long-term evidence of its efficacy is still insufficient. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/ identifier [CRD42021234].

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

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

[Endometriosis and adenomyosis]

Diffuse adenomyosis, focal adenomyosis, ovarian endometrioma, superficial endometriosis and deep infiltrating adenomyosis are all defined by the presence of an endometrioid tissue in an ectopic location that is at distance from the endometrium. Although frequently associated, these lesions represent different clinico-pathological entities that the pathologist should recognized. Herein, we review the clinical and pathological features of these entities, as well as related current physiopathological understandings and differential diagnoses that could be raised by some morphological variants. The statistical association between endometriosis and several ovarian tumors, mainly endometrioid and clear cell carcinomas and seromucinous borderline tumors is well established and we present some molecular and morphological features that support this transformation potential.

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.

Activation of the cGAS-STING signaling pathway in adenomyosis patients

Objective

Adenomyosis is characterized by the presence of endometrium or endometrium‐like glands and stroma within the myometrium. In this study, we aimed to investigate whether the cGAS–STING pathway was activated and correlated with clinical outcomes in adenomyosis patients.

Materials and Methods

Twenty patients diagnosed with adenomyosis and 10 patients diagnosed with cervical intraepithelial neoplasia grade 3 (CIN‐3) but no adenomyosis were enrolled in this study. Specimens were collected during surgery from August 2017 to December 2017 at Third Xiangya Hospital. The messenger RNA (mRNA) and protein levels of key cGAS–STING pathway factors in uterine tissue were detected by real‐time reverse‐transcription polymerase chain reaction and immunohistochemistry, respectively. The correlations of gene expression and clinical outcomes, including dysmenorrhea and uterine volume, were analyzed.

Results

The cGAS, STING, TANK‐binding kinase 1 (TBK‐1), interferon‐α (IFN‐α), IFN‐β, and tumor necrosis factor‐α (TNF‐α) mRNA and protein levels in the ectopic endometrial tissue from adenomyosis patients were significantly higher compared with that from the controls in endometrium (p < .05). cGAS and STING gene expression were correlated with TBK‐1, IFN‐β, and TNF‐α expression (p < .05). Importantly, TBK‐1 and TNF‐α expression were correlated with the clinical outcome of dysmenorrhea (p < .05).

Conclusion

Our study reveals that the cGAS–STING pathway is activated in adenomyosis patients and its activation is subsequently correlated with clinical outcomes, which suggests that the cGAS–STING pathway may contribute to adenomyosis pathogenesis.

Upregulated Talin1 synergistically boosts β-estradiol-induced proliferation and pro-angiogenesis of eutopic and ectopic endometrial stromal cells in adenomyosis

Adenomyosis (ADS) is an estrogen-dependent gynecological disease with unspecified etiopathogenesis. Local hyperestrogenism may serve a key role in contributing to the origin of ADS. Talin1 is mostly identified to be overexpressed and involved in the progression of numerous human carcinomas through mediating cell proliferation, adhesion and motility. Whether Talin1 exerts an oncogenic role in the pathogenesis of ADS and puts an extra impact on the efficacy of estrogen, no relevant data are available yet. Here we demonstrated that the adenomyotic eutopic and ectopic endometrial stromal cells (ADS_Eu_ESC and ADS_Ec_ESC) treated with β-estradiol (β-E₂) presented stronger proliferative and pro-angiogenetic capacities, accompanied by increased expression of PCNA, Ki67, VEGFB and ANGPTL4 proteins. Meanwhile, these promoting effects were partially abrogated by Fulvestrant (ICI 182780, an estrogen-receptor antagonist). Aberrantly upregulation of Talin1 mRNA and protein level was observed in ADS endometrial specimens and stromal cells. Through performing functional experiments in vitro, we further determined that merely overexpression of Talin1 (OV-Talin1) also enhanced ADS stromal cell proliferation and pro-angiogenesis, while the most pronounced facilitating effects were found in the co-intervention group of OV-Talin1 plus β-E₂ treatment. Results from the xenograft nude mice model showed that the hypodermic endometrial lesions from co-intervention group had the highest mean weight and volume, compared with that of individual OV-Talin1 or β-E₂ treatment. The expression levels of PCNA, Ki67, VEGFB and ANGPTL4 in the lesions were correspondingly elevated the most in the co-intervention group. Our findings unveiled that overexpressed Talin1 might cooperate withβ-E₂ in stimulating ADS endometrial stromal cell proliferation and neovascularization, synergistically promoting the growth and survival of ectopic lesions. These results may be beneficial to provide a new insight for clarifying the pathogenesis of ADS.

Three-dimensional understanding of the morphological complexity of the human uterine endometrium

The fundamental morphology of the endometrial glands is not sufficiently understood by 2D observation because these glands have complicated winding and branching patterns. To construct a large picture of the endometrial gland structure, we performed tissue-clearing-based 3D imaging of human uterine endometrial tissue. Our 3D immunohistochemistry and layer analyses revealed that the endometrial glands form a plexus network in the stratum basalis and expand horizontally along the muscular layer, similar to the rhizome of grass. We then extended our method to assess the 3D morphology of tissue affected by adenomyosis, a representative "endometrium-related disease," and observed its 3D morphological features, including the direct invasion of endometrial glands into the myometrium and an ant colony-like network of ectopic endometrial glands within the myometrium. Thus, further understanding of the morphology of the human endometrium based on 3D analysis will lead to the identification of the pathogenesis of endometrium-related diseases.

Organoids of the Female Reproductive Tract: Innovative Tools to Study Desired to Unwelcome Processes

The pelviperineal organs of the female reproductive tract form an essential cornerstone of human procreation. The system comprises the ectodermal external genitalia, the Müllerian upper-vaginal, cervical, endometrial and oviductal derivatives, and the endodermal ovaries. Each of these organs presents with a unique course of biological development as well as of malignant degeneration. For many decades, various preclinical in vitro models have been employed to study female reproductive organ (patho-)biology, however, facing important shortcomings of limited expandability, loss of representativeness and inadequate translatability to the clinic. The recent emergence of 3D organoid models has propelled the field forward by generating powerful research tools that in vitro replicate healthy as well as diseased human tissues and are amenable to state-of-the-art experimental interventions. Here, we in detail review organoid modeling of the different female reproductive organs from healthy and tumorigenic backgrounds, and project perspectives for both scientists and clinicians.

The Potential Relationship Between Different Human Female Reproductive Disorders and Sperm Quality in Female Genital Tract

Spermatozoa should travel throughout the female reproductive tract to reach its ultimate goal, fertilization of the oocyte. At the ejaculation moment, millions of sperm within a few milliliters of the ejaculate are deposited at the cranial segment of vagina and make their journey to the fertilization site. This is done by means of various factors, such as sperm motility, the uterine and fallopian tubes contractility, and the ciliary movement of the lining cells. During this migration, spermatozoa interact with the female microenvironment both physically and molecularly. In this regard, the quality of the environmental conditions may affect this interaction. Therefore, some alterations in women's genital tract microenvironment, such as conditions that occur in female reproductive disorders, may have detrimental effects on sperm reproductive function. In this review, human sperm migration through the female tract is described, and the potential effects of different reproductive disorders at reproductive organs, such as vagina, uterine cervix, uterus, fallopian tubes, and ovary on sperm survival and quality, are also argued. The understanding of those conditions that may impair sperm fertility in the female genital tract can provide a more accurate diagnosis of the causes of infertility in couples. This can ultimately lead to the discovery of effective treatment approaches.

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.

MiR-30c-5p Directly Targets MAPK1 to Regulate the Proliferation, Migration and Invasion of Adenomyotic Epithelial Cells in Adenomyosis

The purpose of our study was to elucidate the functions of miR-30c-5p on adenomyosis for exploring novel treatment strategies. We first detected the expression of miR-30c-5p in clinical adenomyotic tissues and isolated endometrial cells from adenomyotic tissues. Next, gain and loss-of-function assays were performed to detect the effect of miR-30c-5p on adenomyotic endometrial cells. Further, luciferase assay and real-time polymerase chain reaction as well as western blot were conducted to investigate the potential target of miR-30c-5p; and transwell assay, wound-healing assay and CCK-8 assay were used to evaluate the effects of miR-30c-5p and its target on regulating biological functions of adenomyotic endometrial cells. Our results found that miR-30c-5p was down-regulated in both adenomyosis tissues and adenomyotic epithelial cells, which correlated with dysmenorrhea, longer duration of symptoms and more menstrual bleeding. Moreover, the overexpression of miR-30c-5p inhibited the proliferation, migration and invasion of adenomyotic epithelial cells, where miR-30c-5p knockdown had an opposite effect. Furthermore, we confirmed mitogen-activated protein kinase 1 (MAPK1) was one of the direct targets of miR-30c-5p, indicating its important role in miR-30c-5p-mediated suppression of proliferation, invasion and migration in adenomyotic epithelial cells. This study showed that the interaction of miR-30c-5p with MAPK1 can regulate the proliferation, invasion and migration in adenomyotic epithelial cells.

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.

Single-cell transcriptomic analysis of eutopic endometrium and ectopic lesions of adenomyosis

BACKGROUND

Adenomyosis (AM) is a common benign chronic gynaecological disorder; however, the precise pathogenesis of adenomyosis is still poorly understood. Single-cell RNA sequencing (scRNA-seq) can uncover rare subpopulations, explore genetic and functional heterogeneity, and reveal the uniqueness of each cell. It provides us a new approach to reveal biological issues from a more detailed and microscopic perspective. Here, we utilize this revolutionary technology to identify the changes of gene expression patterns between ectopic lesions and the eutopic endometrium at the single-cell level and explore a potential novel pathogenesis of AM.

METHODS

A control endometrium (sample with leiomyoma excluding endometrial disorders, n = 1), eutopic endometrium and ectopic lesion (from a patient with adenomyosis, n = 1) samples were analysed by scRNA-seq, and additional leiomyoma (n = 3) and adenomyosis (n = 3) samples were used to confirm colocalization and vasculogenic mimicry (VM) formation. Protein colocalization was visualized by immunofluorescence, and CD34-periodic acid-Schiff (PAS) double staining was used to assess the formation of VM.

RESULTS

The scRNA-seq results suggest that cancer-, cell motility- and inflammation- (CMI) associated terms, cell proliferation and angiogenesis play important roles in the progression of AM. Moreover, the colocalization of EPCAM and PECAM1 increased significantly in the ectopic endometrium group (P < 0.05), cell subpopulation with high copy number variation (CNV) levels possessing tumour-like features existed in the ectopic lesion sample, and VNN1- and EPCAM-positive cell subcluster displayed active cell motility in endometrial epithelial cells. Furthermore, during the transformation of epithelial cells to endothelial cells, we observed the significant accumulation of VM formation (positively stained with PAS but not CD34, P < 0.05) in ectopic lesions.

CONCLUSIONS

In the present study, our results support the theory of adenomyosis derived from the invasion and migration of the endometrium. Moreover, cell subcluster with high CNV level and tumour-associated characteristics is identified. Furthermore, epithelial-endothelial transition (EET) and the formation of VM in tumours, the latter of which facilitates the blood supply and plays an important role in maintaining cell growth, were also confirmed to occur in AM. These results indicated that the inhibition of EET and VM formation may be a potential strategy for AM management.

Uterine adenomyosis with extensive glandular proliferation: case series of a rare imaging variant

PURPOSE

We aimed to investigate the clinical and magnetic resonance imaging (MRI) characteristics of uterine adenomyosis, in which there is an extensive area of high signal intensity in the myometrium on T2-weighted MRI.

METHODS

This retrospective radiographic study reviewed a case series of six patients (mean age, 36 years) with adenomyosis. These patients were selected because, unlike in classical adenomyosis, T2-weighted images showed a larger area of high signal intensity than that of low signal intensity in the myometrium. The morphology of the myometrial lesions, patterns of contrast enhancement (n=4), intramyometrial hemorrhaging, diffusion restriction (n=5), endometrial lesions, and imaging findings after treatment (n=3) were evaluated on MRI.

RESULTS

The patients' clinical symptoms included vaginal bleeding and severe anemia. Four were administered hormonal therapy, one underwent hysterectomy, and one underwent enucleation. On T2-weighted images, all showed endometrial thickening and a high signal intensity area in the myometrium that was divided up by a mesh of low signal intensity bands, with an appearance reminiscent of a fish caught in a net. Other findings included gradual centripetal enhancement with contrast defects in multicystic areas (4/4), an intramyometrial hemorrhage (1/6), and increased diffusion (5/5). Following hormonal therapy, the uteruses decreased in size and were similar to those of classical adenomyosis on MRI (3/3). The lesions were diagnosed as adenomyosis with a proliferation of adenomyotic glandular tissue and a proliferative endometrial polyp.

CONCLUSION

This case series suggests that there is a subgroup of uterine adenomyosis that shows a characteristic "fish-in-a-net" appearance on T2-weighted images.

LncRNA MIR22HG is downregulated in adenomyosis and upregulates miR-2861 through demethylation to inhibit endometrial cell proliferation

AIM

Endometrial cell proliferation plays a critical role in adenomyosis. It has been reported that MIR22HG and miR-2861 play similar roles in regulating endometrial cell proliferation, indicating their involvement in adenomyosis. This study aimed to investigate the potential involvement of MIR22HG and miR-2861 in adenomyosis.

METHODS

Endometrial biopsy was collected from both adenomyosis (n = 45) and the healthy controls (n = 45). The expression of MIR22HG and miR-2861 in biopsies were determined by quantitative reverse transcription polymerase chain reaction (RT-qPCR). The relationship between MIR22HG and miR-2861 in endometrial cells was analyzed by RT-qPCR. Methylation-specific PCR (MSP) was performed to analyze the effects of overexpression of MIR22HG on the expression of miR-2861. Western-blot assays were performed to illustrate the effect of MIR22HG, miR-2861, STAT3, and MMP2 on adenomyosis. Luciferase report assay was performed to analyze the interactions among miR-2861, STAT3, and MMP2. The role of MIR22HG and miR-2861 in regulating the proliferation of endometrial cells was analyzed by cell proliferation assay.

RESULTS

The expression of MIR22HG and miR-2861 in adenomyosis did not change with menstrual cycle. MIR22HG and miR-2861 were significantly downregulated in adenomyosis and they were significantly and positively correlated with each other. In endometrial cells, overexpression of MIR22HG upregulated the expression of miR-2861 and decreased methylation of miR-2861 gene. MIR22HG and miR-2861 downregulated STAT3 and MMP2 to inhibit the proliferation of endometrial cells. In addition, overexpression of both MIR22HG and miR-2861 showed stronger effects.

CONCLUSION

MIR22HG is downregulated in adenomyosis and upregulates miR-2861 through demethylation to inhibit endometrial cell proliferation.

Possible involvement of neuropeptide and neurotransmitter receptors in Adenomyosis

BACKGROUND

Accumulating data indicate that sensory nerve derived neuropeptides such as substance P and calcitonin gene related-protein (CGRP) can accelerate the progression of endometriosis via their respective receptors, so can agonists to their respective receptors receptor 1 (NK1R), receptor activity modifying protein 1 (RAMP-1) and calcitonin receptor-like receptor (CRLR). Adrenergic β2 receptor (ADRB2) agonists also can facilitate lesional progression. In contrast, women with endometriosis appear to have depressed vagal activity, concordant with reduced expression of α7 nicotinic acetylcholine receptor (α7nAChR). The roles of these receptors in adenomyosis are completely unknown.

METHODS

Adenomyotic tissue samples from 30 women with adenomyosis and control endometrial tissue samples from 24 women without adenomyosis were collected and subjected to immunohistochemistry analysis of RAMP1, CRLR, NK1R, ADRB2 and α7nAChR, along with their demographic and clinical information. The extent of tissue fibrosis was evaluated by Masson trichrome staining.

RESULTS

We found that the staining levels of NK1R, CRLR, RAMP1 and ADRB2 were all significantly elevated in adenomyotic lesions as compared with control endometrium. In contrast, α7nAChR staining levels were significantly reduced. The severity of dysmenorrhea correlated positively with lesional ADRB2 staining levels.

CONCLUSIONS

Our results suggest that SP, CGRP and noradrenaline may promote, while acetylcholine may stall, the progression of adenomyosis through their respective receptors on adenomyotic lesions. Additionally, through the activation of the hypothalamic-pituitary-adrenal (HPA)-sympatho-adrenal-medullary (SAM) axes and the lesional overexpression of ADRB2, adenomyosis-associated dysmenorrhea and adenomyotic lesions may be mutually promotional, forming a viscous feed-forward cycle.

Tools, techniques, and future opportunities for characterizing the mechanobiology of uterine myometrium

The myometrium is the smooth muscle layer of the uterus that generates the contractions that drive processes such as menstruation and childbirth. Aberrant contractions of the myometrium can result in preterm birth, insufficient progression of labor, or other difficulties that can lead to maternal or fetal complications or even death. To investigate the underlying mechanisms of these conditions, the most common model systems have conventionally been animal models and human tissue strips, which have limitations mostly related to relevance and scalability, respectively. Myometrial smooth muscle cells have also been isolated from patient biopsies and cultured in vitro as a more controlled experimental system. However, in vitro approaches have focused primarily on measuring the effects of biochemical stimuli and neglected biomechanical stimuli, despite the extensive evidence indicating that remodeling of tissue rigidity or excessive strain is associated with uterine disorders. In this review, we first describe the existing approaches for modeling human myometrium with animal models and human tissue strips and compare their advantages and disadvantages. Next, we introduce existing in vitro techniques and assays for assessing contractility and summarize their applications in elucidating the role of biochemical or biomechanical stimuli on human myometrium. Finally, we conclude by proposing the translation of "organ on chip" approaches to myometrial smooth muscle cells as new paradigms for establishing their fundamental mechanobiology and to serve as next-generation platforms for drug development.

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.