Menstrual physiology: implications for endometrial pathology and beyond

Prospects for potential therapy targeting immune‑associated factors in endometriosis (Review)

Endometriosis (EM) is a chronic inflammatory disease that is one of the most common causes of gynecological systemic lesions in women before menopause. The most representative histological feature of EM is that the endometrium appears outside of the uterine cavity, often in the ovary. Although it is generally accepted that the epithelial and stromal cells of the ectopic endometrium are not malignant, they still have numerous similarities to malignant tumors, including considerable changes to the immune microenvironment (immune monitoring disorder), the creation of a specific hormone environment, high levels of oxidative stress, chronic inflammation and abnormal immune cell regulation. The pathogenesis of EM is not fully understood, which makes it difficult to identify specific biomarkers and potential therapeutic targets for early disease diagnosis and effective treatment. However, considerable progress has been made in this field over the past few decades. The purpose of the present review is to summarize the confirmed and potential biomarkers for EM, and to identify potential therapeutic targets based on changes in immunological factors (including natural killer cells, macrophages, the complement system, miRNA and P‑selectin) in the ectopic endometrial tissue. It is hoped that this work can be used as the basis for identifying accurate diagnostic markers for EM and developing personalized immune‑targeted therapy.

HSD11B1 overexpression in dendritic cells and stromal cells relates to endometriosis by inhibiting dendritic cell proliferation and maturation

AIMS

This study aims to explore the alterations of dendritic cells (DCs) subpopulations in ectopic endometrial lesions and unveil the underlying mechanisms.

MATERIALS AND METHODS

Patients with endometriosis (n = 81) and women without endometriosis (n = 19) were recruited in this study. Dendritic cells (DCs) in the endometrial samples were counted after immunohistochemistry staining. The proportion of myeloid DCs and plasmacytoid DCs was calculated by flow cytometry. Primary DCs were isolated from tissues, and the cell viability and apoptosis were examined by MTT assay and flow cytometry. Cytokines were detected by the enzyme-linked immunosorbent assay. Differentially expressed genes were filtered by analyzing two datasets that were downloaded from GEO database and detected by RT-qPCR in tissues and isolated DCs. The function of HSD11B1 was examined in an endometrial stromal cell-DCs co-culture system and in vitro cultured DCs.

RESULTS

Reduced myeloid DCs and increased CD11c-CD304-DCs were found in ectopic endometrium compared to control endometrium and eutopic endometrium from endometriosis patients. Myeloid DCs isolated from ectopic endometrium expressed less CD80, CD83, CD86 and had reduced proliferation, increased apoptosis, and reduced cytokine production. The expression of HSD11B1 was significantly increased in both ectopic endometrium and isolated myeloid DCs. Overexpression of HSD11B1 in immature DCs could repress DCs maturation and cytokine production. Endometrial stromal cells overexpressing HSD11B1 secreted increased cortisol, which repressed DCs maturation.

CONCLUSIONS

HSD11B1 is upregulated in ectopic endometrial lesions, which may contribute to endometriosis through repressing myeloid DCs maturation.

Hallmarks of female reproductive aging in physiologic aging mice

The female reproductive axis is one of the first organ systems to age, which has consequences for fertility and overall health. Here, we provide a comprehensive overview of the biological process of female reproductive aging across reproductive organs, tissues and cells based on research with widely used physiologic aging mouse models, and describe the mechanisms that underpin these phenotypes. Overall, aging is associated with dysregulation of the hypothalamic-pituitary-ovarian axis, perturbations of the ovarian stroma, reduced egg quantity and quality, and altered uterine morphology and function that contributes to reduced capacity for fertilization and impaired embryo development. Ultimately, these age-related phenotypes contribute to altered pregnancy outcomes and adverse consequences in offspring. Conserved mechanisms of aging, as well as those unique to the reproductive system, underlie these phenotypes. The knowledge of such mechanisms will lead to development of therapeutics to extend female reproductive longevity and support endocrine function and overall health.

The Application of Nano Drug Delivery Systems in Female Upper Genital Tract Disorders

The prevalence of female reproductive system disorders is increasing, especially among women of reproductive age, significantly impacting their quality of life and overall health. Managing these diseases effectively is challenging due to the complex nature of the female reproductive system, characterized by dynamic physiological environments and intricate anatomical structures. Innovative drug delivery approaches are necessary to facilitate the precise regulation and manipulation of biological tissues. Nanotechnology is increasingly considered to manage reproductive system disorders, for example, nanomaterial imaging allows for early detection and enhances diagnostic precision to determine disease severity and progression. Additionally, nano drug delivery systems are gaining attention for their ability to target the reproductive system successfully, thereby increasing therapeutic efficacy and decreasing side effects. This comprehensive review outlines the anatomy of the female upper genital tract by highlighting the complex mucosal barriers and their impact on systemic and local drug delivery. Advances in nano drug delivery are described for their sustainable therapeutic action and increased biocompatibility to highlight the potential of nano drug delivery strategies in managing female upper genital tract disorders.

Cellular heterogeneity and dynamics of the human uterus in healthy premenopausal women

The human uterus is a complex and dynamic organ whose lining grows, remodels, and regenerates every menstrual cycle or upon tissue damage. Here, we applied single-cell RNA sequencing to profile more the 50,000 uterine cells from both the endometrium and myometrium of five healthy premenopausal individuals, and jointly analyzed the data with a previously published dataset from 15 subjects. The resulting normal uterus cell atlas contains more than 167K cells, representing the lymphatic endothelium, blood endothelium, stromal, ciliated epithelium, unciliated epithelium, and immune cell populations. Focused analyses within each major cell type and comparisons with subtype labels from prior studies allowed us to document supporting evidence, resolve naming conflicts, and propose a consensus annotation system of 39 subtypes. We release their gene expression centroids, differentially expressed genes, and messenger Ribonucleic Acid (mRNA) patterns of literature-based markers as a shared community resource. We identify multiple potential progenitor cells: compartment-wide progenitors for each major cell type and potential cross-lineage multipotent stromal progenitors that may replenish the epithelial, stromal, and endothelial compartments. Furthermore, many cell types and subtypes exhibit shifts in cell number and transcriptomes across different phases of the menstrual cycle. Finally, comparisons between premenopausal, postpartum, and postmenopausal samples revealed substantial alterations in tissue composition, particularly in the proportions of stromal, endothelial, and immune cells. The cell taxonomy and molecular markers we report here are expected to inform studies of both basic biology of uterine function and its disorders.

Sleep is altered during menstruation but not inflammatory parameters: Results from polysomnography of EPISONO database

Menstruation is an inflammatory process that involves changes in women's physiology leading to mental and physical complaints. Sleep is essential for optimal hormonal release, immune response, and wellbeing, becoming an important factor to be evaluated. We compared sleep, inflammatory mediators, fatigue, anxiety and depression symptoms, and quality of life in menstruating and non-menstruating women. We used the polysomnographic data of 232 women from EPISONO 2007, an epidemiological study from São Paulo city, Brazil. Women were distributed into menstruating (N = 61) and non-menstruating groups (N = 171). We applied questionnaires related to sleep quality, sleepiness, insomnia, fatigue, anxiety and depression symptoms, and quality of life. The serum levels of interleukin 6, tumour necrosis factor-alpha, and C-reactive protein were analysed. For statistical analysis the significance level adopted was p < 0.05. Sleep efficiency was statistically lower in menstruating women (81% ± 13) compared with the non-menstruating group (84.2% ± 13.3, p < 0.023). No statistical differences between the two groups were found in respect to the other parameters analysed. Both groups scored for fatigue symptoms, but no statistical significance was observed between the groups. Our findings indicate that menstruation was associated with lower objective sleep efficiency, suggesting that menstruation may be a physiological factor impairing sleep. Further studies evaluating menstrual variables, and each phase of the menstrual cycle, should be undertaken to detect the main factors associated with sleep complaints, fatigue, and objective parameters of sleep.

Clusterin from endometrial glands plays a critical role in decidualization via Trem2

BACKGROUND

Decidualization is a critical step in establishing pregnancy in mammals. Successful decidualization depends on intricate gland-stromal crosstalk. Clusterin (Clu) is a ubiquitously secreted protein in physiological fluids that is involved in numerous physiological functions. However, the role of Clu in decidualization is not fully understood.

RESULTS

In this study, we examined the expression pattern of Clu during early pregnancy in mice and explored its potential function in decidualization. Our results revealed that Clu was expressed in the uterine glands on Days 1-2 of early pregnancy and on Days 5-8 during decidualization after embryo implantation, as well as in glands at the interimplantation site. Additionally, ovariectomized mice exhibited significant upregulation of Clu expression in the uterine glands 3 h after in vivo estrogen injection. Trem2, a receptor for Clu, was detected in the decidual region of mice on Days 5-8 of early pregnancy, where it mediates Clu to regulate the decidual region. Furthermore, we observed that recombinant CLU protein increased the expression of the decidualization marker molecules insulin-like growth factor binding protein 1 (IGFBP1) and prolactin (PRL) in decidual cells. However, this upregulation was not observed when Trem2 expression was inhibited with siRNA.

CONCLUSIONS

Uterine gland-derived Clu, a new paracrine modulator, may participate in early pregnancy by influencing the decidualization process mediated by Trem2 in mice.

Human Endometrial Pericytes: A Comprehensive Overview of Their Physiological Functions and Implications in Uterine Disorders

Pericytes are versatile cells integral to the blood vessel walls of the microcirculation, where they exhibit specific stem cell traits. They are essential in modulating blood flow, ensuring vascular permeability, and maintaining homeostasis and are involved in the tissue repair process. The human endometrium is a unique and complex tissue that serves as a natural scar-free healing model with its cyclical repair and regeneration process every month. The regulation of pericytes has gained increasing attention due to their involvement in various physiological and pathological processes. However, endometrial pericytes are less well studied compared to the pericytes in other organs. This review aims to provide a comprehensive overview of endometrial pericytes, with a focus on elucidating their physiological function and potential implications in uterine disorders.

ST6GALNAC1-mediated sialylation in uterine endometrial epithelium facilitates the epithelium-embryo attachment

INTRODUCTION

Embryo implantation requires synergistic interaction between the embryo and the receptive endometrium. Glycoproteins and glycan-binding proteins are involved in endometrium-embryo attachment. Sialyl Tn (sTn), a truncated O-glycan, is catalyzed by ST6 N-Acetylgalactosaminide Alpha-2,6-Sialyltransferase 1 (ST6GALNAC1) and can be detected by specific Sialic-acid-binding immunoglobulin-like lectins (Siglecs). Whether the sTn-Siglecs axis supports embryo implantation remains unknown.

OBJECTIVES

This paper aims to study the role of ST6GALNAC1/sTn-Siglecs axis in embryo implantation.

METHODS

ST6GALNAC1 and sTn in human endometrium were analyzed by immunohistochemistry. An in vitro implantation model was conducted to evaluate the effects of ST6GALNAC1/sTn on the receptivity of human endometrial AN3CA cells to JAR spheroids. Immunoprecipitation combined with mass spectrometry analysis was carried out to identify the key proteins modified by sTn in endometrial cells. Siglec-6 in human embryos was analyzed by published single-cell RNA sequencing (scRNA-seq) datasets. Protein interaction assay was applied to verify the bond between the Siglec-6 with sTn-modified CD44. St6galnac1 siRNAs and anti-sTn antibodies were injected into the uterine horn of the mouse at the pre-implantation stage to evaluate the role of endometrial St6galnac1/sTn in embryo implantation. Siglec-G in murine embryos was analyzed by immunofluorescence staining. The function of Siglec-G is evidenced by uterine horn injection and protein interaction assay.

RESULTS

Both human and murine endometrium at the receptive stage exhibit higher ST6GALNAC1 and sTn levels compared to the non-receptive stage. Overexpression of ST6GALNAC1 significantly enhanced the receptivity of AN3CA cells to JAR spheroids. Inhibition of endometrial ST6GALNAC1/sTn substantially impaired embryo implantation in vivo. CD44 was identified as a carrier for sTn in the endometrial cells of both species. Siglec-6 and Siglec-G, expressed in the embryonic trophectoderm, were found to promote embryo attachment, which may be achieved through binding with sTn-modified CD44.

CONCLUSION

ST6GALNAC1-regulated sTn in the endometrium aids in embryo attachment through interaction with trophoblastic Siglecs.

Human umbilical cord mesenchymal stem cells improve uterine incision healing after cesarean delivery in rats by modulating the TGF-β/Smad signaling pathway

OBJECTIVE

Although human umbilical cord-derived mesenchymal stem cells (HU-MSCs) have attracted increasing attention because of their pivotal functions in the process of wound healing, the underlying molecular mechanisms have been poorly understood. It has been shown that the TGF-β/Smad signaling pathway plays an important role in the process of scar formation. The present study focused on exploring whether HU-MSCs improve uterine incision healing after cesarean delivery in rats via the TGF-β/Smad signaling pathway.

STUDY DESIGN

Pregnant rats were randomly assigned to three groups, including the NP group, incision-injected group (HU-MSCs1 group), and tail vein-injected group (HU-MSCs2 group), and 30 days after cesarean section, sampling was carried out to further explore the specific mechanisms from tissue and protein levels.

RESULTS

HU-MSCs secretion could inhibit the fibrosis of scar tissue. We observed that the TGF-β induced expression of TGF-β1, Smad2, and Smad3 was attenuated upon HU-MSCs treatment in scar tissue, while the decrease in TGF-β3 expression was enhanced by HU-MSCs. Furthermore, HU-MSCs treatment accelerated wound healing and attenuated collagen deposition in a damaged uterine rat model, leading to the promoting of uterine incision scarring. In addition, the expression of alpha-smooth muscle actin (a-SMA) was enhanced by HU-MSCs treatment.

CONCLUSION

HU-MSCs transplantation promotes rat cesarean section uterine incision scar healing by modulating the TGF-β/Smad signaling pathway.

How do phases of the menstrual cycle affect sleep? A polysomnographic study of the EPISONO database

PURPOSE

Our study aimed to evaluate the impact of the menstrual cycle stages, especially menses, on sleep, inflammatory mediators, fatigue, anxiety, depression, and quality of life.

METHODS

We used data from the EPISONO study cohort, selecting 96 women who had undergone one-night polysomnography. The women were distributed in three groups according to the time point of the menstrual cycle on the polysomnography night: menses, mid/late follicular phase, and luteal phase. The volunteers completed questionnaires related to sleep quality, daytime sleepiness, insomnia, fatigue, anxiety, depression, and quality of life. Blood samples were collected to analyze interleukin 6, tumor necrosis factor-alpha, and C-reactive protein.

RESULTS

Sleep efficiency was statistically higher in women in the mid/late follicular group (89.9% ± 9.6) compared to menstrual (83.0% ± 10.8) and luteal (83.7% ± 12.7) groups. The mid/late follicular group presented a statistically significant reduction in sleep onset latency (7.1 ± 7.1 min) compared to the menstrual (22.3 ± 32.4 min) and luteal groups (15.9 ± 14.7 min). No statistical differences among the three groups were observed in other polysomnographic parameters, inflammatory mediators, daytime sleepiness, insomnia, fatigue, anxiety, depression, and quality of life.

CONCLUSIONS

Our findings demonstrate that the mid/late follicular phase might be beneficial for women's sleep, although there were no statistically changes in inflammatory mediators among the groups.

Therapeutic Potential of Hydrogen Sulfide in Reproductive System Disorders

Hydrogen sulfide (H2S), previously regarded as a toxic exhaust and atmospheric pollutant, has emerged as the third gaseous signaling molecule following nitric oxide (NO) and carbon monoxide (CO). Recent research has revealed significant biological effects of H2S in a variety of systems, such as the nervous, cardiovascular, and digestive systems. Additionally, H2S has been found to impact reproductive system function and may have therapeutic implications for reproductive disorders. This paper explores the relationship between H2S and male reproductive disorders, specifically erectile dysfunction, prostate cancer, male infertility, and testicular damage. Additionally, it examines the impact of H2S regulation on the pathophysiology of the female reproductive system, including improvements in preterm birth, endometriosis, pre-eclampsia, fetal growth restriction, unexplained recurrent spontaneous abortion, placental oxidative damage, embryo implantation, recovery of myometrium post-delivery, and ovulation. The study delves into the regulatory functions of H2S within the reproductive systems of both genders, including its impact on the NO/cGMP pathway, the activation of K+ channels, and the relaxation mechanism of the spongy smooth muscle through the ROCK pathway, aiming to broaden the scope of potential therapeutic strategies for treating reproductive system disorders in clinical settings.

Comparing the risk of deep vein thrombosis of two combined oral contraceptives: Norethindrone/ethinyl estradiol and drospirenone/ethinyl estradiol

Background

Deep vein thrombosis (DVT) has been reported as an adverse event for patients receiving combined oral contraceptives. Norethindrone/ethinyl estradiol (NET/EE) and drospirenone/ethinyl estradiol (DRSP/EE) are two commonly prescribed combined hormonal oral contraceptive agents used in the United States, differing in their progestin component.

Objective

The purpose of this study was to determine the association between the progestin component of a combined oral contraceptive and the risk of DVT in patients taking oral contraceptives for birth control using data derived from the FDA Adverse Event Reporting System (FAERS).

Methods

The risk of DVT was compared between patients that had taken NET/EE with those that had taken the DRSP/EE COC formulation for birth control. In addition, age was assessed as a possible confounder and the outcome severity for those diagnosed with DVT were compared between the two groups. Finally, association rule mining was utilized to identify possible drug-drug interactions that result in elevated DVT risk.

Results

DVT was the fourth most commonly adverse event reported for patients taking DRSP/EE accounting for 8558 cases and the seventeenth most commonly reported adverse event for NET/EE accounting for 298 cases. Age was found to be a significant confounder for users of DRSP/EE with regards to DVT risk across all age groups assessed: 2040 (ROR = 3.69, 95% CI 3.37-4.04) However, there was only a statistically significant elevated risk in patients over 40 years of age taking NET/EE (ROR = 1.98, 95% CI 1.36-2.88). Patients that had taken DRSP/EE and the corticosteroid prednisone simultaneously had an approximately 3-fold increase in DVT risk (ROR = 2.77, 95% CI 2.43-3.15) relative to individuals that had only taken DRSP/EE.

Conclusion

Based on this analysis, there is a higher risk of developing DVT when taking DRSP/EE than when taking NET/EE as hormonal contraception. In addition, a possibly significant drug-drug interaction between different COC formulations and prednisone were identified. This interaction may result in elevated DVT risk due to a synergistic impairment of fibrinolysis and a decrease in plasmin production.

Cellular heterogeneity and dynamics of the human uterus in healthy premenopausal women

The human uterus is a complex and dynamic organ whose lining grows, remodels, and regenerates in every menstrual cycle or upon tissue damage. Here we applied single-cell RNA sequencing to profile more the 50,000 uterine cells from both the endometrium and myometrium of 5 healthy premenopausal individuals, and jointly analyzed the data with a previously published dataset from 15 subjects. The resulting normal uterus cell atlas contains more than 167K cells representing the lymphatic endothelium, blood endothelium, stromal, ciliated epithelium, unciliated epithelium, and immune cell populations. Focused analyses within each major cell type and comparisons with subtype labels from prior studies allowed us to document supporting evidence, resolve naming conflicts, and to propose a consensus annotation system of 39 subtypes. We release their gene expression centroids, differentially expressed genes, and mRNA patterns of literature-based markers as a shared community resource. We find many subtypes show dynamic changes over different phases of the cycle and identify multiple potential progenitor cells: compartment-wide progenitors for each major cell type, transitional cells that are upstream of other subtypes, and potential cross-lineage multipotent stromal progenitors that may be capable of replenishing the epithelial, stromal, and endothelial compartments. When compared to the healthy premenopausal samples, a postpartum and a postmenopausal uterus sample revealed substantially altered tissue composition, involving the rise or fall of stromal, endothelial, and immune cells. The cell taxonomy and molecular markers we report here are expected to inform studies of both basic biology of uterine function and its disorders.

SIGNIFICANCE

We present single-cell RNA sequencing data from seven individuals (five healthy pre-menopausal women, one post-menopausal woman, and one postpartum) and perform an integrated analysis of this data alongside 15 previously published scRNA-seq datasets. We identified 39 distinct cell subtypes across four major cell types in the uterus. By using RNA velocity analysis and centroid-centroid comparisons we identify multiple computationally predicted progenitor populations for each of the major cell compartments, as well as potential cross-compartment, multi-potent progenitors. While the function and interactions of these cell populations remain to be validated through future experiments, the markers and their "dual characteristics" that we describe will serve as a rich resource to the scientific community. Importantly, we address a significant challenge in the field: reconciling multiple uterine cell taxonomies being proposed. To achieve this, we focused on integrating historical and contemporary knowledge across multiple studies. By providing detailed evidence used for cell classification we lay the groundwork for establishing a stable, consensus cell atlas of the human uterus.

Is endometriosis due to evolutionary maladaptation?

Similar to diabetes and unlike many pathogen-induced diseases, endometriosis is likely a result of maladaptation to the evolutionary heritage of humans. The objective of this article is to review the literature and improve understanding of the evolutionary factors behind endometriosis, leading to more effective prevention and treatment approaches. In primates, spontaneous decidualization of the endometrium evolved to ensure optimal implantation of a limited number of early embryos, unlike many non-primates which depend on early embryos to induce decidualization and subsequent pregnancy. Spontaneous decidualization results in menstrual bleeding when embryo implantation does not occur, and endometriosis is commonly believed to be caused by retrograde menstruation. Although direct evidence is lacking, it is likely that hunter-gatherer women experienced fewer menstrual periods due to pregnancy shortly after menarche, followed by repeated pregnancies and lactation. However, the mismatch between the evolved uterine physiology and rapid societal changes has led to modern women delaying pregnancy and experiencing numerous menstrual periods, potentially increasing the incidence of endometriosis. The symptoms of endometriosis are often managed by suppressing menstruation through systemic hormonal treatments, but these may have side effects. For patients with a family history of endometriosis or in the early stages of the disease, intrauterine devices releasing progesterone locally could prevent uterine bleeding and the development of endometriosis while preserving fertility and minimizing side effects.

E2-Loaded Microcapsules and Bone Marrow-Derived Mesenchymal Stem Cells with Injectable Scaffolds for Endometrial Regeneration Application

Bone marrow-derived mesenchymal stem cells (BMSCs) have been recognized as new candidates for the treatment of serious endometrial injuries. However, owing to the local microenvironment of damaged endometrium, transplantation of BMSCs yielded disappointing results. In this study, Pectin-Pluronic® F-127 hydrogel as scaffolds were fabricated to provide three-dimensional architecture for the attachment, growth, and migration of BMSCs. E2 was encapsulated into the W/O/W microspheres to construct pectin-based E2-loaded microcapsules (E2 MPs), which has the potential to serve as a long-term reliable source of E2 for endometrial regeneration. Then, the BMSCs/E2 MPs/scaffolds system was injected into the uterine cavity of mouse endometrial injury model for treatment. At 4 weeks after transplantation, the system increased proliferative abilities of uterine endometrial cells, facilitated microvasculature regeneration, and restored the ability of endometrium to receive an embryo, suggesting that the BMSCs/E2 MPs/scaffolds system is a promising treatment option for endometrial regeneration. Furthermore, the mechanism of E2 in promoting the repair of endometrial injury was also investigated. Exosomes are critical paracrine mediators that act as biochemical cues to direct stem cell differentiation. In this study, it was found that the expression of endometrial epithelial cell (EEC) markers was upregulated in BMSCs treated by exosomes secreted from endometrial stromal cells (ESCs-Exos). Exosomes derived from E2-stimulated ESCs further promoted the expression level of EECs markers in BMSCs, suggesting exosomes released from ESCs by E2 stimulation could enhance the differentiation efficiency of BMSCs. Therefore, exosomes derived from ESCs play paracrine roles in endometrial regeneration stimulated by E2 and provide optimal estrogenic response.

Endometrial Stem Cells: Orchestrating Dynamic Regeneration of Endometrium and Their Implications in Diverse Endometrial Disorders

The human endometrium, a vital component of the uterus, undergoes dynamic changes during the menstrual cycle to create a receptive environment for embryo implantation. Its remarkable regenerative capacity can be attributed to the presence of tissue-resident stem cell populations within the endometrium. Despite variations in characteristics among different subtypes, endometrial stem cells exhibit notably robust self-renewal capacity and the ability to differentiate into multiple lineages. This review offers a comprehensive insight into the current literature and recent advancements regarding the roles of various endometrial stem cell types during dynamic regeneration of the endometrium during the menstrual cycle. In addition, emerging evidence suggests that dysfunction or depletion of endometrial stem cells may play critical roles in the development and progression of various endometrial disorders, such as endometriosis, uterine fibroids, adenomyosis, infertility, and endometrial cancer. Therefore, we also highlight potential roles of endometrial stem cells in the development and progression of these endometrial diseases, including their ability to accumulate genetic mutations and express genes associated with endometrial diseases. Understanding the dynamic properties of the endometrium and the roles of endometrial stem cells in various endometrial disorders will shed light on potential therapeutic strategies for managing these conditions and improving women's fertility outcomes.

Effects of SARS-CoV-2 Vaccination on Menstrual Cycle: An Italian Survey-Based Study

Vaccination against SARS-CoV-2 has played a critical role in controlling the spread of the pandemic. The main side effects of SARS-CoV-2 vaccination include fever and fatigue; however, the potential impacts on menstrual cycles are to be determined. Given the limited number of studies suggesting menstrual changes post vaccination, this study investigates the correlation between COVID-19 vaccines and menstrual cycle changes in fertile-aged Italian women. A questionnaire was distributed from 1 October to 31 November 2022, focusing on menstrual rhythm and flow changes post vaccination. The analysis involved 471 participants. The study observed a shift from a regular to an irregular menstrual rhythm (p < 0.001), and changes in menstrual duration (p = 0.008 and p < 0.001 for first and second doses, respectively) and flow volume (p < 0.001). Most patients with irregular rhythms were vaccinated in the proliferative phase of their cycle. Within six months post vaccination, 74.2% of women with irregular post-vaccination rhythms reported a return to normality. These findings indicate primarily transient menstrual changes following mRNA COVID-19 vaccination, suggesting the vaccines' safety for women of reproductive age.

Breaking the silence: The role of extracellular vesicles in unraveling the diagnosis and treatment of endometriosis

Cell-to-cell communication is believed to be facilitated by membrane-bound vesicles called extracellular vesicles (EVs), which are released by cells. Protein, lipids, and nucleic acids are major cargo of EVs and are transported in these vesicles. Depending on the parent and recipient cell types, they can affect a wide variety of biological processes in the tissues to which they are delivered. EVs are essential for embryo implantation and endometriosis, and they are located in the uterine cavities of different species, where they promote blastocyst and endometrial preparation for implantation. This review focuses on what is currently understood regarding pathologic and diagnostic characteristics, and the potential therapeutic value of EVs in the context of endometriosis, where they can be used for drug delivery and targeted therapy due to their ability to carry bioactive molecules to specific cells or tissues. The findings of this review highlight the potential for a wide range of clinical applications that involve endometrial EVs in the areas of treatment, such as surgical and pharmacological, diagnostic biomarker development, and drug delivery systems, all with the ultimate goal of improving pregnancy success rates.

Digestive system deep infiltrating endometriosis: What do we know

Digestive system infiltrating endometriosis (DSIE) is an uncommon form of endometriosis in the digestive system. DSIE often occurs in the intestines (especially the sigmoid rectum), liver, gallbladder and pancreas. Clinically, DSIE presents with the same symptoms as endometriosis, including cyclic pain, bleeding and infertility, in addition to specific biliary/intestinal obstruction and gastrointestinal bleeding. Compared to general endometriosis, DSIE has unique biological behaviour and pathophysiological mechanisms. Most DSIEs are deep invasive endometrioses, characterized by metastasis to the lymph nodes and lymphatic vessels, angiogenesis, peripheral nerve recruitment, fibrosis and invasion of surrounding tissues. DSIE-related peripheral angiogenesis is divided into three patterns: angiogenesis, vasculogenesis and inosculation. These patterns are regulated by interactions between multiple hypoxia-hormone cytokines. The nerve growth factors regulate the extensive neurofibril recruitment in DSIE lesions, which accounts for severe symptoms of deep pain. They are also associated with fibrosis and the aggressiveness of DSIE. Cyclic changes in DSIE lesions, recurrent inflammation and oxidative stress promote repeated tissue injury and repair (ReTIAR) mechanisms in the lesions, accelerating fibril formation and cancer-related mutations. Similar to malignant tumours, DSIE can also exhibit aggressiveness derived from collective cell migration mediated by E-cadherin and N-cadherin. This often makes DSIE misdiagnosed as a malignant tumour of the digestive system in clinical practice. In addition to surgery, novel treatments are urgently required to effectively eradicate this lesion.

The role and participation of immune cells in the endometrial tumor microenvironment

The tumor microenvironment is surrounded by blood vessels and consists of malignant, non-malignant, and immune cells, as well as signalling molecules, which primarily affect the therapeutic response and curative effects of drugs in clinical studies. Tumor-infiltrating immune cells participate in tumor progression, impact anticancer therapy, and eventually lead to the development of immune tolerance. Immunotherapy is evolving as a promising therapeutic intervention to stimulate and activate the immune system to suppress cancer cell growth. Endometrial cancer (EC) is an immunogenic disease, and in recent years, immunotherapy has shown benefit in the treatment of recurrent and advanced EC. This review discusses the key molecular pathways associated with the intra-tumoral immune response and the involvement of circulatory signalling molecules. Specific immunologic signatures in EC which offer targets for immunomodulating agents, are also discussed. We have summarized the available literature in support of using immunotherapy in EC. Lastly, we have also discussed ongoing clinical trials that may offer additional promising immunotherapy options in the future. The manuscript also explored innovative approaches for screening and identifying effective drugs, and to reduce the financial burdens for the development of personalized treatment strategies. Collectively, we aim to provide a comprehensive review of the role of immune cells and the tumor microenvironment in the development, progression, and treatment of EC.

The progestin revolution 2: progestins are now a dominant player in the tight interlink between contraceptive protection and bleeding control-plus more

The interlink between bleeding control and contraceptive development has always been an important factor. But after many years of advances in contraceptive technology, this interplay has resulted in development of safer and better contraceptive methods that often offer significantly less bleeding for women with both normal bleeding patterns as well as in those suffering from heavy menstrual bleeding (HMB). Recognition of the success of progestin-only methods, such as the hormonal IUDs, progestin dominant oral contraceptives, and the high dose progestin-only pill in substantially decreasing and controlling menstrual bleeding has led the way. This recognition also led to the development of many [non-contraceptive] protocols to stop acute heavy bleeding as well as manage long-term bleeding [using contraceptive methods as well; as non-contraceptive methods].But even better, there is a new PLUS. The distinct benefit and risk profiles of the many different progestins now available are intentionally being used either in combination contraceptive pills [COCPs] or alone, to add additional benefits, to decrease side effects and risks, and increase effectiveness and bleeding control.

α1,3-fucosylation of MEST promotes invasion potential of cytotrophoblast cells by activating translation initiation

Embryo implantation into the uterus is the gateway for successful pregnancy. Proper migration and invasion of embryonic trophoblast cells are the key for embryo implantation, and dysfunction causes pregnancy failure. Protein glycosylation plays crucial roles in reproduction. However, it remains unclear whether the glycosylation of trophoblasts is involved in trophoblast migration and invasion processes during embryo implantation failure. By Lectin array, we discovered the decreased α1,3-fucosylation, especially difucosylated Lewis Y (LeY) glycan, in the villus tissues of miscarriage patients when compared with normal pregnancy women. Downregulating LeY biosynthesis by silencing the key enzyme fucosyltransferase IV (FUT4) inhibited migration and invasion ability of trophoblast cells. Using proteomics and translatomics, the specific LeY scaffolding glycoprotein of mesoderm-specific transcript (MEST) with glycosylation site at Asn163 was identified, and its expression enhanced migration and invasion ability of trophoblast cells. The results also provided novel evidence showing that decreased LeY modification on MEST hampered the binding of MEST with translation factor eIF4E2, and inhibited implantation-related gene translation initiation, which caused pregnancy failure. The α1,3-fucosylation of MEST by FUT4 may serve as a new biomarker for evaluating the functional state of pregnancy, and a target for infertility treatment.

S100A8 and S100A9 are associated with endometrial shedding during menstruation

Matrix metalloproteinases (MMPs) and their major source, endometrial stromal cells (ESCs), play important roles in menstruation. However, other mechanisms in endometrial shedding may be unexplored. This study focused on four proteins: S100A8 and S100A9 (alarmins) are binding partners and induce MMPs, MMP-3 cycle-dependently plays a key role in the proteolytic cascade, and CD147, which has S100A9 as its ligand, induces MMPs. Immunostaining for these proteins was performed on 118 resected specimens. The percentage and location of each positive reaction in ESCs were measured and compared using Image J. The influence of leukocytes on S100A8 or S100A9 immunopositivity was also examined. From the premenstrual phase, S100A8 and MMP-3 began to have overlapping expressions in ESCs of the superficial layer, and ESC detachment was found within these sites. S100A9 was expressed from the late secretory phase and CD147 already from earlier. Later, the expression sites of S100A9 and CD147 included those of S100A8. Before menstruation, S100A8 or S100A9 expression was not affected by leukocytes. These results suggest that the local formation of S100A8/S100A9 complex, which occurs specifically in ESCs upon progesterone withdrawal, induces the local expression of MMP-3 and serves as a switch to the lysis phase.

Using organoids to investigate human endometrial receptivity

The human endometrium is only receptive to an implanting blastocyst in the mid-secretory phase of each menstrual cycle. Such time-dependent alterations in function require intricate interplay of various factors, largely coordinated by estrogen and progesterone. Abnormal endometrial receptivity is thought to contribute to two-thirds of the implantation failure in humans and therefore significantly hindering IVF success. Despite the incontrovertible importance of endometrial receptivity in implantation, the precise mechanisms involved in the regulation of endometrial receptivity remain poorly defined. This is mainly due to a lack of proper in vitro models that recapitulate the in vivo environment of the receptive human endometrium. Organoids were recently established from human endometrium with promising features to better mimic the receptive phase. Endometrial organoids show long-term expandability and the capability to preserve the structural and functional characteristics of the endometrial tissue of origin. This three-dimensional model maintains a good responsiveness to steroid hormones in vitro and replicates key morphological features of the receptive endometrium in vivo, including pinopodes and pseudostratified epithelium. Here, we review the current findings of endometrial organoid studies that have been focused on investigating endometrial receptivity and place an emphasis on methods to further refine and improve this model.

Menstrual disturbances following COVID-19 vaccination: A probable puzzle about the role of endocrine and immune pathways

Menstruation is a monthly shedding of the uterine wall, presented by menstrual bleeding in women of reproductive age. Menstruation is regulated by fluctuation of estrogen and progesterone, as well as other endocrine and immune pathways. Many women experienced menstrual disturbances after vaccination against the novel coronavirus in the last two years. Vaccine-induced menstrual disturbances have led to discomfort and concern among reproductive-age women, such that some decided not to receive the subsequent doses of the vaccine. Although many vaccinated women report these menstrual disturbances, the mechanism is still poorly understood. This review article discusses the endocrine and immune changes following COVID-19 vaccination and the possible mechanisms of vaccine-related menstrual disturbances.

Long-Term Follow-Up Result of Connective Tissue Manipulation in Young Women with Primary Dysmenorrhea: Different Intervention Durations

The purpose of this study was to reveal the effect of connective tissue manipulation (CTM) on long-term pain severity, fatigue, sleep quality, premenstrual symptom severity, general health status, anxiety, and depression in women with primary dysmenorrhea (PD). Thirty-five women with PD were divided into two groups. CTM was applied to the participants in each group on the days when they were not on menstruation between two menstrual cycles for the group 1 (n=18) and between three menstrual cycles for the group 2 (n=17). Intensity of menstrual pain, the sleep quality, and fatigue status of the participants during dysmenorrhea were evaluated by the Visual Analog Scale (VAS). Depressive symptoms and anxiety were evaluated using the Beck Depression Inventory (BDI) and the Beck Anxiety Inventory (BAI), respectively. Also, the Premenstrual Syndrome Scale (PMSS) and the General Health Questionnaire (GHQ) were used to investigate the severity of premenstrual symptoms and mental health status during menstrual period. A significant decrease in the pain severity and fatigue of the participants was observed in both group 1 and group 2 after treatment, after 3rd, and 6th month follow-up (p=0.001). Also, this decrease lasted for 12th month follow-up after treatment in group 2 (p=0.0001). There was no statistically significant improvement in sleep quality within each group (p>0.05). Moreover, none of the parameters were significantly different between two groups (p>0.05). We can suggest that 2-cycle CTM treatment should be preferred in clinical settings to obtain long-lasting effects for decreasing pain, fatigue, and premenstrual symptoms in women with PD. CLINICAL TRIAL NUMBER: NCT04509934. Registration date: 8 November 2020.

SARS-CoV-2 infection and female reproductive health: A narrative review

The COVID-19 pandemic has had a profound global impact, affecting people's physical and mental health, and their social and economic circumstances. Mitigation measures have disproportionately affected women. Studies have reported menstrual cycle and psychological disturbance associated with the pandemic. Pregnancy is a risk factor for severe COVID-19 disease. Reports have also demonstrated associations between COVID-19 infection, vaccination and Long COVID syndrome and reproductive health disturbance. However, studies are limited and there may be significant geographical variation. Also there is bias amongst published studies, and menstrual cycle data was not included in COVID-19 and vaccine trials. Longitudinal population based studies are required. In this review we discuss existing data, along with recommendations for further research required in this area. We also discuss a pragmatic approach to women presenting with reproductive health disturbance in the era of the pandemic, encompassing a multi-system assessment of psychological, reproductive health and lifestyle.

How Do Microorganisms Influence the Development of Endometriosis? Participation of Genital, Intestinal and Oral Microbiota in Metabolic Regulation and Immunopathogenesis of Endometriosis

Microorganisms inhabiting the human body play an extremely key role in its proper functioning, as well as in the development of the immune system, which, by maintaining the immune balance, allows you to enjoy health. Dysbiosis of the intestinal microbiota, or in the oral cavity or reproductive tract, understood as a change in the number and diversity of all microorganisms inhabiting them, may correlate with the development of many diseases, including endometriosis, as researchers have emphasized. Endometriosis is an inflammatory, estrogen-dependent gynecological condition defined by the growth of endometrial cells outside the uterine cavity. Deregulation of immune homeostasis resulting from microbiological disorders may generate chronic inflammation, thus creating an environment conducive to the increased adhesion and angiogenesis involved in the development of endometriosis. In addition, research in recent years has implicated bacterial contamination and immune activation, reduced gastrointestinal function by cytokines, altered estrogen metabolism and signaling, and abnormal progenitor and stem cell homeostasis, in the pathogenesis of endometriosis. The aim of this review was to present the influence of intestinal, oral and genital microbiota dysbiosis in the metabolic regulation and immunopathogenesis of endometriosis.

Association of classic and 11-oxygenated androgens with polycystic ovaries and menstrual cycle prolongation in infertile women with PCOS

BACKGROUND AND AIMS

The etiology of polycystic ovary syndrome (PCOS) is unclear. This study aimed to evaluate the role of classic and 11-oxygenated (11oxyC19) androgens in two typical signs of PCOS, polycystic ovary morphology (PCOM) and menstrual cycle prolongation.

MATERIALS AND METHODS

A total of 462 infertile women with diagnosed PCOS and/or commonly accompanied metabolic disorders were recruited. Classic and 11oxyC19 androgens were determined with a sensitive high-performance liquid chromatography-differential mobility spectrometry tandem mass spectrometry apparatus. Least absolute shrinkage and selection operator logistic regression with fivefold cross-validation was applied to construct prediction models.

RESULTS

For PCOM, the most significant contributing androgen was testosterone (T), with the weight of 51.6%. The AUC of the prediction model was 0.824 in validation set. For menstrual cycle prolongation, androstenedione (A4) was the most significant contributing androgen with weights of 77.5%. The AUC the prediction model was less than 0.75. When including other variables, the most significant variable turned to be AMH both in PCOM and in menstrual cycle prolongation.

CONCLUSION

Androgens had more contribution in PCOM than in menstrual cycle prolongation. The classic androgen T or A4 contributed more than 11oxyC19 androgens. However, their contributions were diminished when other factors were considered, especially AMH.

An Appraisal of the Tissue Injury and Repair (TIAR) Theory on the Pathogenesis of Endometriosis and Adenomyosis

As understanding their pathogenesis remains elusive, both endometriosis and adenomyosis are often referred to as "enigmatic diseases". The uncertainty and heightened interest are reflected in the range of expressed views and opinions. There is a sense of urgency because of the entailed patient suffering. The plethora of opinions calls for a critical analysis of proposed theories, both old and new. A series of papers published since 2009 proposed that both endometriosis and adenomyosis originate from the same aberrations occurring within the uterus. This came to be recognized as the tissue injury and repair theory, and the newly coined term "archimetrosis" posits that the two diseases share the same origin. While the theory opens an interesting channel for exploration, its claim as a unifying theory necessitates a critical appraisal. We, thus, undertook this review of the theory and analyzed its underpinnings based on a comprehensive review of the literature. Our appraisal indicates that the theory is open to a range of criticisms. Chief among these is the need for confirmatory evidence of features of abnormal uterine contractility and the lack of data addressing the question of causality. In addition, the theory has, as yet, no supporting epidemiological evidence, which is a major weakness. The theory suffers as it is not open to the test of falsifiability, and it lacks the ability to make useful predictions. It has not addressed the questions, such as why only a small percentage of women develop adenomyosis or endometriosis, given the ubiquity of uterine peristalsis. On the other hand, the triggers and prevention of hyper- or dys-peristalsis become critical to a theory of causation. We conclude that additional supportive evidence is required for the theory to be accepted.

Vascular changes in the cycling and early pregnant uterus

Uterine vascular remodeling is intrinsic to the cycling and early pregnant endometrium. Maternal regulatory factors such as ovarian hormones, VEGF, angiopoietins, Notch, and uterine natural killer cells significantly mediate these vascular changes. In the absence of pregnancy, changes in uterine vessel morphology and function correlate with different stages of the human menstrual cycle. During early pregnancy, vascular remodeling in rodents and humans results in decreased uterine vascular resistance and increased vascular permeability necessary for pregnancy success. Aberrations in these adaptive vascular processes contribute to increased risk of infertility, abnormal fetal growth, and/or preeclampsia. This Review comprehensively summarizes uterine vascular remodeling in the human menstrual cycle, and in the peri- and post-implantation stages in rodent species (mice and rats).

Cyclic processes in the uterine tubes, endometrium, myometrium, and cervix: pathways and perturbations

This review leads the 2023 Call for Papers in MHR: 'Cyclical function of the female reproductive tract' and will outline the complex and fascinating changes that take place in the reproductive tract during the menstrual cycle. We will also explore associated reproductive tract abnormalities that impact or are impacted by the menstrual cycle. Between menarche and menopause, women and people who menstruate living in high-income countries can expect to experience ∼450 menstrual cycles. The primary function of the menstrual cycle is to prepare the reproductive system for pregnancy in the event of fertilization. In the absence of pregnancy, ovarian hormone levels fall, triggering the end of the menstrual cycle and onset of menstruation. We have chosen to exclude the ovaries and focus on the other structures that make up the reproductive tract: uterine tubes, endometrium, myometrium, and cervix, which also functionally change in response to fluctuations in ovarian hormone production across the menstrual cycle. This inaugural paper for the 2023 MHR special collection will discuss our current understanding of the normal physiological processes involved in uterine cyclicity (limited specifically to the uterine tubes, endometrium, myometrium, and cervix) in humans, and other mammals where relevant. We will emphasize where knowledge gaps exist and highlight the impact that reproductive tract and uterine cycle perturbations have on health and fertility.

Relationship between covid-pandemic anxiety and sleep disorder with menstrual disorders among female medical workers

BACKGROUND

It has been more than 2 years since the 2019 novel coronavirus disease (COVID-19) pandemic destabilized the world, adversely affecting not only physical health, but also mental health. During this time, frontline medical workers were at a greater health risk, especially female medical workers. Changes or abnormalities in the menstrual cycle-an important indicator of women's health-may jeopardize female reproductive functioning. Considering that emotional health and sleep status may be related to the menstrual cycle, this study aimed to investigate the association between menstrual cycle changes, anxiety, sleep dysfunction, and other factors among female medical workers during the COVID-19 pandemic.

METHODS

A cross-sectional survey was conducted by distributing online questionnaires to female medical workers in China from February to May 2022. The study included 160 women aged 18-45 years old. The questionnaires covered data related to the participants' sociodemographic characteristics, medical and reproductive history, and lifestyle. The Rating Scale for Clinical Manifestations of Menopathy (SCMM), Self-Rating Anxiety Scale (SAS), and Sleep Dysfunction Rating Scale (SDRS) were utilized. Data were analyzed using chi-square tests, t-tests, and linear regression analysis.

RESULTS

A total of 160 female medical staff were randomly selected in this research, of whom seven scored less than 3 points, 85 scored 3-11 points, and 68 scored more than 11 points on the total score of the SCMM. Compared to pre-pandemic scores, scores of dizziness and tinnitus were significantly higher during the COVID-19 pandemic. Scores corresponding to the following clinical symptoms were also higher during the pandemic: Menopathy, including hypaphrodisia, dim complexion, abnormal urination, languidness, dim menstruation, thin menstruation, dysmenorrhea, and empty or saggy lower abdomen (p < 0.05). However, pre-pandemic scores of vaginal bleeding quantity were significantly higher than those found during the COVID-19 pandemic (p < 0.05). Scores of vaginal bleeding quantity were significantly lower in cabin hospitals than other types of hospitals, and a similar finding was observed for vaginal bleeding duration (all p < 0.05). Moreover, the findings of the univariable and multivariable linear regression analysis revealed a link between consistent exercise, the underlying illness, the SDRS score, the SAS score, and the total score of SCMM (p < 0.05).

CONCLUSIONS

In this study, we found that menstruation in female medical workers was affected by the COVID-19 pandemic. Furthermore, regular exercise and good physical condition were protective factors, while anxiety and insomnia were risk factors for menstrual abnormalities.

Development of cell-laden multimodular Lego-like customizable endometrial tissue assembly for successful tissue regeneration

BACKGROUND

The endometrium, the inner lining of the uterine cavity, plays essential roles in embryo implantation and its subsequent development. Although some positive results were preliminarily archived, the regeneration of damaged endometrial tissues by administrating stem cells only is very challenging due to the lack of specific microenvironments and their low attachment rates at the sites of injury. In this context, various biomaterial-based scaffolds have been used to overcome these limitations by providing simple structural support for cell attachment. However, these scaffold-based strategies also cannot properly reflect patient tissue-specific structural complexity and thus show only limited therapeutic effects.

METHOD

Therefore, in the present study, we developed a customizable Lego-like multimodular endometrial tissue architecture by assembling individually fabricated tissue blocks.

RESULTS

Each tissue block was fabricated by incorporating biodegradable biomaterials and certain endometrial constituent cells. Each small tissue block was effectively fabricated by integrating conventional mold casting and 3D printing techniques. The fabricated individual tissue blocks were properly assembled into a larger customized tissue architecture. This structure not only properly mimics the patient-specific multicellular microenvironment of the endometrial tissue but also properly responds to key reproductive hormones in a manner similar to the physiological functions.

CONCLUSION

This customizable modular tissue assembly allows easy and scalable configuration of a complex patient-specific tissue microenvironment, thus accelerating various tissue regeneration procedures.

Macrophages and small extracellular vesicle mediated-intracellular communication in the peritoneal microenvironment: Impact on endometriosis development

Endometriosis is an inflammatory disease that is defined as the growth of endometrium-like tissue outside the uterus, commonly on the lining of the pelvic cavity, visceral organs and in the ovaries. It affects around 190 million women of reproductive age worldwide and is associated with chronic pelvic pain and infertility, which greatly impairs health-related life quality. The symptoms of the disease are variable, this combined with a lack of diagnostic biomarkers and necessity of surgical visualisation to confirm disease, the prognosis can take an average timespan of 6-8 years. Accurate non-invasive diagnostic tests and the identification of effective therapeutic targets are essential for disease management. To achieve this, one of the priorities is to define the underlying pathophysiological mechanisms that contribute to endometriosis. Recently, immune dysregulation in the peritoneal cavity has been linked to endometriosis progression. Macrophages account for over 50% of immune cells in the peritoneal fluid and are critical for lesion growth, angiogenesis, innervation and immune regulation. Apart from the secretion of soluble factors like cytokines and chemokines, macrophages can communicate with other cells and prime disease microenvironments, such as the tumour microenvironment, via the secretion of small extracellular vesicles (sEVs). The sEV-mediated intracellular communication pathways between macrophages and other cells within the peritoneal microenvironment in endometriosis remain unclear. Here, we give an overview of peritoneal macrophage (pMΦ) phenotypes in endometriosis and discuss the role of sEVs in the intracellular communication within disease microenvironments and the impact they may have on endometriosis progression.

Human development and reproduction in space-a European perspective

This review summarises key aspects of the first reproductive and developmental systems Science Community White Paper, supported by the European Space Agency (ESA). Current knowledge regarding human development and reproduction in space is mapped to the roadmap. It acknowledges that sex and gender have implications on all physiological systems, however, gender identity falls outside the scope of the document included in the white paper collection supported by ESA. The ESA SciSpacE white papers on human developmental and reproductive functions in space aim to reflect on the implications of space travel on the male and female reproductive systems, including the hypothalamic-pituitary-gonadal (HPG) reproductive hormone axis, and considerations for conception, gestation and birth. Finally, parallels are drawn as to how this may impact society as a whole on Earth.

Decreased Glycolysis at Menstruation is Associated with Increased Menstrual Blood Loss

Heavy menstrual bleeding (HMB) is common and severely affects the quality of life of the afflicted women. While HMB is known to be caused by impaired endometrial repair after menstruation, its more proximate cause remains unknown. To investigate whether glycolysis plays any role in endometrial repair and thus HMB, we conducted two mouse experiments using a mouse model of simulated menstruation. We performed immunohistochemistry analyses of proteins involved in glycolysis as well as pro- and anti-inflammatory cytokines in endometrium from decidualized and non-decidualized uterine horns. We also assessed the extent of endometrial repair by staging endometrial morphology from decidualization to full repair using histological scoring of uterine sections and quantitated the amount of menstrual blood loss (MBL). In addition, we employed the scratch assay and the CCK-8 assay to evaluate the effect of glycolysis suppression on cellular migration and proliferation, respectively. Finally, we performed an immunohistochemistry analysis of HK2 in endometrium from women with adenomyosis who experienced either moderate/heavy or excessive MBL. We found that endometrial repair coincided with increased glycolysis in endometrium and glycolysis suppression delayed endometrial repair, resulting in increased MBL. Additionally, glycolysis suppression significantly inhibited the proliferative and migratory capability of endometrial cells, and disrupted normal endometrial repair even when hypoxia was maintained. Women with adenomyosis who experienced excessive MBL had significantly lower HK2 staining than those who experienced moderate/heavy MBL. Thus, our study highlights the importance of glycolysis as well as inflammation in optimal endometrial repair, and provides clues for the cause of HMB in women with adenomyosis.

Endometrial Inflammation and Impaired Spontaneous Decidualization: Insights into the Pathogenesis of Adenomyosis

Adenomyosis is an estrogen-dependent gynecologic disease characterized by the myometrial invasion of the endometrial tissue. This review summarized the current understanding and recent findings on the pathophysiology of adenomyosis, focusing on repeated menstruation, persistent inflammation, and impaired spontaneous decidualization. A literature search was performed in the PubMed and Google Scholar databases from inception to 30 April 2022. Thirty-one full-text articles met the eligibility criteria. Repeated episodes of physiological events (i.e., endometrial shedding, damage, proliferation, differentiation, repair, and regeneration) during the menstrual cycle are associated with inflammation, angiogenesis, and immune processes. The decidualization process in humans is driven by the rise in progesterone levels, independently of pregnancy (i.e., spontaneous decidualization). Adenomyotic cells produce angiogenic and fibrogenic factors with the downregulation of decidualization-associated molecules. This decidualization dysfunction and persistent inflammation are closely related to the pathogenesis of adenomyosis. Recently, it has been found that the reproductive tract microbiota composition and function in women with adenomyosis differ from those without. An increase in opportunistic pathogens and a decrease in beneficial commensals may promote impaired defense mechanisms against inflammation and predispose women to uncontrolled endometrial inflammation. However, currently, there is no direct evidence that adenomyosis is linked to pre-existing inflammation and impaired spontaneous decidualization. Overall, persistent inflammation, impaired spontaneous decidualization, and microbiota dysbiosis (i.e., an imbalance in the composition and function of endometrial microbiota) may be involved in the pathophysiology of adenomyosis.

"GONE WITH THE WIND": The Transitory Effects of COVID-19 on the Gynecological System

The coronavirus disease no longer seems to represent an insurmountable global problem. This is thanks to the advent of coronavirus vaccines, which have alleviated the most serious symptoms associated with this disease. On the other hand, there are still many extrapulmonary symptoms of COVID-19, and among these also those of a gynecological nature. At the moment, there are several questions in this field, one above all concerns the causal link between COVID-19, vaccines and gynecological alterations. Furthermore, another important aspect is represented by the clinical impact of post-COVID-19 gynecological alterations on the female population which, to date, would seem to be mainly due to their duration, even if the extent of these symptoms is still poorly understood. Furthermore, it is not possible to foresee eventual long-term aggravations, or more serious symptoms caused by other viral variants that may arrive in the future. In this review, we focus on this theme and attempt to reorganize the different pieces of a puzzle which, to date, does not seem to have shown us its complete picture.

Progress and prospect of technical and regulatory challenges on tissue-engineered cartilage as therapeutic combination product

Hyaline cartilage plays a critical role in maintaining joint function and pain. However, the lack of blood supply, nerves, and lymphatic vessels greatly limited the self-repair and regeneration of damaged cartilage, giving rise to various tricky issues in medicine. In the past 30 years, numerous treatment techniques and commercial products have been developed and practiced in the clinic for promoting defected cartilage repair and regeneration. Here, the current therapies and their relevant advantages and disadvantages will be summarized, particularly the tissue engineering strategies. Furthermore, the fabrication of tissue-engineered cartilage under research or in the clinic was discussed based on the traid of tissue engineering, that is the materials, seed cells, and bioactive factors. Finally, the commercialized cartilage repair products were listed and the regulatory issues and challenges of tissue-engineered cartilage repair products and clinical application would be reviewed.

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Tissue engineered cartilage, a promising strategy for articular cartilage repair.

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Nearly 20 engineered cartilage repair products in clinic based on clinical techniques.

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Combination product, the classification of tissue-engineered cartilage.

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Key regulatory compliance issues for combination products.

Sensitive HPLC-DMS/MS/MS method coupled with dispersive magnetic solid phase extraction followed by in situ derivatization for the simultaneous determination of multiplexing androgens and 17-hydroxyprogesterone in human serum and its application to patients with polycystic ovarian syndrome

BACKGROUND AND AIMS

Androgens play important roles in polycystic ovarian syndrome (PCOS). However, measures of androgens based on mass spectrometry (MS) remain complex due to endogenous inferences of isomers or compounds with similar structures. Lack of sensitivity can also affect the accurate quantification of androgens, especially for very low level of 11-oxygenated androgens.

MATERIALS AND METHODS

We developed a fast and sensitive high-performance liquid chromatography-differential mobility spectrometry tandem mass spectrometry (HPLC-DMS/MS/MS) method for the simultaneous determination of seven androgens and 17-hydroxyprogesterone. Dispersive magnetic solid phase extraction (DMSPE) was conducted with core-shell structured nanoparticles of magnetic graphene oxide (Fe₃O₄@GO). In situ derivatization was performed using Girard's Reagent P.

RESULTS

Linear ranges of the eight analytes were set in terms of clinical use. Intra- and inter-run precisions were < 16.7 % and 12.9 % for all the analytes and relative error was - 14.7-13.3 % and - 9.3-11.0 %, respectively. Extraction recoveries were 54.0-92.7 % for different analytes. The method was validated and was applied to assay 432 clinical samples.

CONCLUSION

The developed method is green, fast, sensitive and accurate for the determination of endogenous androgens. It can be readily implemented in medical laboratories to provide superior analytical performance over the traditional electrochemiluminescence immunoassay method.

A Histopathological Study of Endometrial Biopsy Samples in Abnormal Uterine Bleeding

BACKGROUND

Abnormal uterine bleeding (AUB) is the most common health issue in women, defined as any bleeding pattern that differs in frequency, duration, and amount. Endometrial sampling and its histopathological examination is the first-line test in patients presenting with AUB. The aim of this study was to analyze the histopathological patterns of endometrium in women with AUB and to find the predominant histopathologic pattern in the different age groups of women with AUB.

METHODS

The study was conducted at the Indira Gandhi Medical College and Research Institute, Puducherry, from January 2019 to December 2020. Endometrial biopsies of patients with AUB, in whom gestational causes were ruled out, were included in this study.

RESULTS

Out of the 160 cases analyzed, the maximum number of biopsies were from the age group of 41-50 years; the majority of patients presented with complaints of menorrhagia. The bleeding pattern was significantly associated with age groups (p=0.00). Of 160 cases, 104 cases were related to functional causes. The association of functional and organic causes with age group was not significant (p=0.67 and p=0.99, respectively). The most common histological pattern was the normal cyclical pattern showing proliferative (56) and secretory phase (30) in 86 cases. Of 42 cases of endometrial hyperplasia, 9 cases had atypical hyperplasia. The endometrial polyp was the other common organic lesion observed. Only two cases of endometrial carcinoma were reported during the present study period.

CONCLUSION

Although a regular cyclical pattern is observed commonly, endometrial sampling should be considered in the peri- and post-menopausal age groups wherein the incidence of endometrial hyperplasia and endometrial carcinoma is more common.

Untargeted metabolomics reveals that multiple reproductive toxicants are present at the endometrium

BACKGROUND

Recent epidemiologic research shows many environmental chemicals exhibit endocrine disrupting effects on the female reproductive system. Few studies have examined exposure at reproductive organs. Our aim was to perform a preliminary untargeted metabolomic characterization of menstrual blood, a novel biofluid, to identify environmental toxins present in the endometrium and evaluate the suitability of this sample type for exposome research.

METHODS

Whole blood menstrual samples were collected from four women using a menstrual cup. Samples were analyzed for small molecules that include both environmental chemicals and endogenous metabolites using untargeted liquid chromatography with high-resolution mass spectrometry (LC-HRMS). Principal component analysis (PCA) and ANOVA was used to identify differences within and between individuals' menstrual blood metabolomic profiles, and the influence of the sample processing method. To assess the presence of environmental exposures, LC-HRMS chemical profiles were matched to the ToxCast chemical database, which includes 4557 commonly used commercial chemicals. Select compounds were confirmed by comparison to reference standards.

RESULTS

PCA of metabolome profiles showed analysis of menstrual blood samples were highly reproducible, with high variability in detected metabolites between participants and low variability between analytical replicates of an individual's sample. Endogenous metabolites detected in menstrual blood samples achieved good coverage of the human blood metabolome. We found 1748 annotations for environmental chemicals, including suspected reproductive toxicants such as phenols, parabens, phthalates, and organochlorines. Storage temperature for the first 24 h did not significantly influence global metabolomic profiles.

CONCLUSION

Our results show chemical exposures linked to reproductive toxicity and endocrine disruption are present in menstrual blood, a sampling medium for the endometrium.

From menarche to menopause, heavy menstrual bleeding is the underrated compass in reproductive health

Menstruation is defined as monthly uterine bleeding, regarded as a sign of reproductive health. When characterized by excessive bleeding (heavy menstrual bleeding [HMB]), it may act as a useful clinical marker for diagnosis of reproductive diseases. Endometrial and myometrial mechanisms underlying abnormal uterine bleeding (AUB), which includes HMB, have hormonal, cellular, and molecular aspects. Structural and nonstructural causes of AUB, presenting with HMB as the major symptom, result in iron depletion and consequent anemia. Heavy menstrual bleeding can be considered as a single entity to identify the possible underlying causes, which may be different to some extent to those of AUB, as a whole. Furthermore, the difficulties in defining HMB through objective methods do not allow the current epidemiological scenario on the prevalence of the symptom among reproductive-age women to be outlined. Moreover, the introduction of new diagnostic methods, including imaging technologies, entails a revision of the available figures on HMB in different age groups from menarche to menopause. In addition, a proper diagnostic algorithm for HMB should be implemented to adapt recommendations for clinical investigation when HMB is present.

Uterine disorders and iron deficiency anemia

Abnormal uterine bleeding (AUB) is a clinical entity which can lead to iron deficiency anemia. Classification according to the acronym PALM-COEIN (polyp, adenomyosis, leiomyoma, malignancy, and hyperplasia; coagulopathy, ovulatory dysfunction, endometrial, iatrogenic, and not otherwise classified) provides a structured approach to establish the cause of AUB. The goal of this review is to discuss the different mechanisms and the relationship between uterine disorders and AUB. Heavy menstrual bleeding, a subgroup of AUB, is more closely related to the presence of uterine fibroids. The relationship between heavy menstrual bleeding and uterine fibroids remains poorly characterized, particularly the understanding of endometrial function in women with structural myometrial features such as leiomyomas. A number of theories have been proposed in the literature and are discussed in this review. Uterine adenomyosis is also a frequent cause of AUB, and its pathogenesis is still far from being fully elucidated. The mechanisms contributing to its development are multifactorial. Many theories lean toward invasion of the myometrium by endometrial cells. Both clinical and basic studies favor the theory of direct invasion, although de novo development of adenomyosis from Müllerian rests or stem cells has not been ruled out. Development of adenomyotic lesions involves repeated tissue injury and repair. In addition, this review describes the other causes of AUB such as endometrial polyps, cesarean scar defects, and uterine vascular abnormalities. Endometrial polyps are often asymptomatic, but approximately 68% of women have concomitant AUB. Histologic alterations in the lower uterine segment in patients who had undergone cesarean sections were identified and may explain the cause of AUB.

What Do the Transcriptome and Proteome of Menstrual Blood-Derived Mesenchymal Stem Cells Tell Us about Endometriosis?

Given the importance of menstrual blood in the pathogenesis of endometriosis and the multifunctional roles of menstrual mesenchymal stem cells (MenSCs) in regenerative medicine, this issue has gained prominence in the scientific community. Moreover, recent reviews highlight how robust the integrated assessment of omics data are for endometriosis. To our knowledge, no study has applied the multi-omics approaches to endometriosis MenSCs. This is a case-control study at a university-affiliated hospital. MenSCs transcriptome and proteome data were obtained by RNA-seq and UHPLC-MS/MS detection. Among the differentially expressed proteins and genes, we emphasize ATF3, ID1, ID3, FOSB, SNAI1, NR4A1, EGR1, LAMC3, and ZFP36 genes and MT2A, TYMP, COL1A1, COL6A2, and NID2 proteins that were already reported in the endometriosis. Our functional enrichment analysis reveals integrated modulating signaling pathways such as epithelial-mesenchymal transition (↑) and PI3K signaling via AKT to mTORC1 (↓ in proteome), mTORC1 signaling, TGF beta signaling, TNFA signaling via NFkB, IL6 STAT3 signaling, and response to hypoxia via HIF1A targets (↑ in transcriptome). Our findings highlight primary changes in the endometriosis MenSCs, suggesting that the chronic inflammatory endometrial microenvironment can modulate these cells, providing opportunities for endometriosis etiopathogenesis. Moreover, they identify challenges for future research leveraging knowledge for regenerative and precision medicine in endometriosis.

SFRP4+ stromal cell subpopulation with IGF1 signaling in human endometrial regeneration

Our understanding of full-thickness endometrial regeneration after injury is limited by an incomplete molecular characterization of the cell populations responsible for the organ functions. To help fill this knowledge gap, we characterized 10,551 cells of full-thickness normal human uterine from two menstrual phases (proliferative and secretory phase) using unbiased single cell RNA-sequencing. We dissected cell heterogeneity of main cell types (epithelial, stromal, endothelial, and immune cells) of the full thickness uterine tissues, cell population architectures of human uterus cells across the menstrual cycle. We identified an SFRP4⁺ stromal cell subpopulation that was highly enriched in the regenerative stage of the human endometria during the menstrual cycle, and the SFRP4⁺ stromal cells could significantly enhance the proliferation of human endometrial epithelial organoid in vitro, and promote the regeneration of endometrial epithelial glands and full-thickness endometrial injury through IGF1 signaling pathway in vivo. Our cell atlas of full-thickness uterine tissues revealed the cellular heterogeneities, cell population architectures, and their cell-cell communications during the monthly regeneration of the human endometria, which provide insight into the biology of human endometrial regeneration and the development of regenerative medicine treatments against endometrial damage and intrauterine adhesion.

Mycobiome Dysbiosis in Women with Intrauterine Adhesions

The vaginal microbiota dysbiosis is closely associated with the development of reproductive diseases. However, the contribution of mycobiome to intrauterine adhesion (IUA) disease remains unknown. Harnessing 16S and ITS2 rDNA sequencing analysis, we investigate both bacterial and fungal microbiota compositions across 174 samples taken from both cervical canal (CC) and middle vagina (MV) sites of IUA patients. Overall, there is no significant difference in microbial diversity between healthy subjects (HS) and IUA patients. However, we observe the IUA-specific bacterial alterations such as increased Dialister and decreased Bifidobacterium and enriched fungal genera like increased Filobasidium and Exophiala. Moreover, site-specific fungal-bacterial correlation networks are discovered in both CC and MV samples of IUA patients. Mechanistic investigation shows that Candida parapsilosis, other than Candida albicans and Candida maltosa, prevents the exacerbation of inflammatory activities and fibrosis, and modulates bacterial microbiota during IUA progression in a rat model of IUA. Our study thus highlights the importance of mycobiota in IUA progression, which may facilitate the development of therapeutic target for IUA prevention. IMPORTANCE Intrauterine adhesion (IUA) often leads to hypomenorrhea, amenorrhea, repeat miscarriages, and infertility. It has been prevalent over the last few decades in up to 13% of women who experience pregnancy termination during the first trimester, and 30% of women undergo dilation and curettage after a late, spontaneous abortion. However, the pathogenesis of IUA remains unclear. Despite reports of microbiota dysbiosis during IUA progression, there is little information on the effect of fungal microbiota on the development of IUA. This study not only enhances our understanding of the mycobiome in IUA patients but also provides potential intervention strategies for prevention of IUA by targeting mycobiome.

Role of macrophages in the immunopathogenesis of adenomyosis

The aim of the research: to study pathophysiological mechanisms of adenomyosis development by determining the role of macrophages in the uterine microenvironment. Materials and methods: a prospective study has been conducted on 35 women. There were 20 (57.1 %) who had adenomyosis of I degree. The control group consisted of 15 (34.3 %) gynecologically healthy women. The patients underwent general clinical, instrumental (ultrasound, hysteroscopy) examinations. Fragments of the uterine wall obtained by hysterorectoscopy were used for morphological study. The method of immunohistochemical determination of CD68+ and CD163+ macrophages was used to analyze the characteristics of phenotypic equivalents of M1 and M2 macrophages in uterine tissue samples. Results: The increase in the number of macrophages in the myometrium of patients with adenomyosis revealed in this study, which is found in large numbers in the areas of infiltration of the stroma of myometrial cells in close association with the perivascular region, can be regarded as the basis of the mechanism for the formation of endometrioid heterotopia. Furthermore, distortion of the CD68/CD163 ratio of macrophages is characterized by proinflammatory shift. Conclusions: The study's main result is an increase in the quantitative indicators of CD68+ macrophages associated with adenomyosis, which indicates an immunopathological process in adenomyosis.