Involvement of Transcription Factor 21 in the Pathogenesis of Fibrosis in Endometriosis

Transcription factor addictions: exploring the potential Achilles' Heel of endometriosis

A considerable number of women of reproductive age suffer from endometriosis worldwide. There is a significant physical, mental, and financial burden on patients affected by this condition in terms of pelvic pain, either continuously or intermittently, dysmenorrhea, infertility, and a higher risk of certain types of cancer. Several treatments available in clinical settings for endometriosis management do not provide adequate efficacy and have undesirable side effects. Transcription factors (TFs) are crucial regulators of key biological processes involved in endometriosis. Here, we elaborated on the research progress regarding the crucial roles of TFs in endometriosis, emphasizing their implications for clinical outcomes and critical therapeutic contributions. By delving into their involvement in key processes, such as cell proliferation and apoptosis, we revealed the multifaceted role of key TFs in disease progression. We aimed to provide a systemic understanding of TFs regulation in endometriosis pathogenesis, establishing a foundation for innovative treatment approaches.

A novel senotherapeutic strategy with azithromycin for preventing endometriosis progression

BACKGROUND

Endometriosis is an estrogen-dependent chronic inflammatory disease, however the mechanisms underlying inflammation remain unclear. Non-hormonal drugs that can prevent endometriosis progression and resolve endometriotic infertility are urgently required. We thus focused on cellular senescence as a novel feature of endometriosis. Senescent cells cause chronic inflammation via the senescence-associated secretory phenotype (SASP) factor. It has been reported the effects of senolysis for various diseases in recent years. The aim of this study was to validate the involvement of cellular senescence in endometriosis and as the effects of senolytic drug to develop a novel non-hormonal therapeutic strategy for endometriosis.

METHODS

The senescence markers were assessed by morphological features and semiquantitative immunofluorescence staining (senescence-associated b-galactosidase [SA-b-Gal], the cyclin-dependent kinase inhibitor 2 A locus [p16INK4a], and laminB1) to compare among cell types (normal endometrial stromal cells [nESCs], endometrial stromal cells with endometriosis [eESCs], and ovarian endometriosis [OE] cyst-derived stromal cells [CSCs]). Expression of SASP markers was examined in cell culture supernatants using a cytokine array. In addition, the effects of senolytic drugs (azithromycin [AZM] and navitoclax [ABT263]) on endometriosis were evaluated in vitro and in vivo. The in vivo study used the endometriosis mice model.

RESULTS

CSCs exhibited stronger senescence markers. Semi-quantitative SA-β-Gal and p16INK4a staining intensities were significantly increased, and that of LaminB1 was decreased in CSCs compared to those in nESCs and eESCs (SA-b-Gal, P < 0.001; p16INK4a, P < 0.05; LaminB1, P < 0.05). Cytokine array analysis revealed elevated SASP-related cytokine levels, including interleukin-6 (IL-6), in CSC supernatants compared to those in nESCs. AZM and ABT263 reduced the viable fraction in CSCs (AZM: P < 0.001, ABT263: P < 0.01). Furthermore, AZM suppressed IL-6 expression in CSC culture supernatants (P < 0.05). In murine model, AZM administration reduced endometriotic lesion volume compared to that in vehicle (P < 0.05). Proliferative activity, IL-6 expression levels, and fibrosis within endometriotic lesions also decreased (Ki67, P < 0.01; IL-6, P < 0.001; fibrosis, P < 0.001).

CONCLUSIONS

Our findings show that cellular senescence is involved in the pathogenesis of endometriosis and that AZM may be useful for preventing endometriosis progression by suppressing the secretion of IL-6 as a SASP.

Thymic stromal lymphopoietin contributes to endometriotic lesion proliferation and disease-associated inflammation

Endometriosis is a chronic disorder in which endometrial-like tissue presents outside the uterus. Patients with endometriosis have been shown to exhibit aberrant immune responses within the lesion microenvironment and in circulation which contribute to the development of endometriosis. Thymic stromal lymphopoietin (TSLP) is an alarmin involved in cell proliferation and the induction of T helper 2 (Th2) inflammation in various diseases, such as asthma, atopic dermatitis, and pancreatic and breast cancer. Recent studies have detected TSLP within endometriotic lesions and shown that its concentrations are elevated in the peritoneal fluid of patients compared with control subjects. However, its role in disease pathophysiology remains unclear. Here, we compared TSLP messenger RNA and protein expression between patient eutopic endometrium, endometriotic lesions, and control endometrial samples. We also assessed its effect on the proliferation and apoptosis of human endometriosis-representative cell lines, as well as on lesion development and inflammation in a mouse model of the disease. We demonstrated that TSLP expression was elevated in the stroma of patient endometriotic lesions compared with control endometrial samples. In cell lines, TSLP treatment reduced the apoptosis of endometrial stromal cells and promoted the proliferation of THP-1 cells. In mice induced with endometriosis, TSLP treatment induced a Th2 immune response within the lesion microenvironment, and led to TSLP receptor modulation in macrophages, dendritic cells, and CD4+ T cells. Furthermore, treatment increased murine endometriotic lesion proliferation. Overall, these results suggest that TSLP modulates the endometriotic lesion microenvironment and promotes a Th2 immune response that could support lesion development.

Aberrant TCF21 upregulation in adenomyosis impairs endometrial decidualization by increasing PDE4C expression

BACKGROUND

Impaired decidualization is a major cause of infertility in patients with adenomyosis (AM). However, the effect of transcription factor 21 (TCF21) on AM and the underlying mechanism of associated-impaired decidualization remain unclear. The aim of this study was to investigate the expression of TCF21 in endometrial tissues of AM patients and the specific mechanisms by which it impairs the decidualization of human endometrial stromal cells (HESCs), with a view to improving the reproductive outcome of AM infertile patients.

METHODS

We compared gene expressions via transcriptomics between the control and AM-associated recurrent implantation failure (RIF) groups. qRT-PCR, western blot, and IHC were performed to confirm the expression and location of TCF21 in the endometrium. Furthermore, we confirmed that high expression of TCF21 impairs decidualization by qRT-PCR, immunofluorescence, and western blot. RNA-seq following overexpression of TCF21 in HESCs was conducted to identify TCF21-related molecular changes during in vitro decidualization. Then we performed ChIP-seq/qPCR and dual-luciferase reporter assay to explore the exact interaction between TCF21 and PDE4C. The related downstream mechanisms were further proved using IHC, qRT-PCR, western blot, and ELISA.

RESULTS

According to the RNA-seq analysis, TCF21 expression was remarkably higher in the endometrium of the AM-related RIF group compared to the control group. We confirmed the same results using samples from patients with AM and controls. TCF21 overexpression in HESCs impaired decidualization through suppression of decidual markers and cytoskeleton alterations. The mechanistic analysis revealed that TCF21 inhibited intracellular cAMP levels by directly increasing PDE4C expression and suppressing FOXO1 expression.

CONCLUSIONS

TCF21 compromises decidualization in patients with AM via the PDE4C/cAMP-FOXO1 axis, which offers valuable insights on the pathology of decidualization-related infertility and indicates a potential treatment to improve endometrial receptivity in AM.

[Pathogenesis of fibrosis development in ovarian endometriosis]

Endometriosis-associated fibrosis is a complex phenomenon, and the underlying mechanisms are still not fully understood. Fibrosis is invariably present in all forms of the disease and contributes to the classic endometriosis-associated symptoms such as chronic pelvic pain and infertility. The purpose of this literature review was to study the role of various cell populations, biological mechanisms and signaling pathways in inducing fibrogenesis of endometriosis lesions. PubMed and MEDLINE searched for studies published in English over the past 5 years that studied fibrosis in ovarian endometriosis.

Western diet promotes endometriotic lesion growth in mice and induces depletion of Akkermansia muciniphila in intestinal microbiota

BACKGROUND

Endometriosis, affecting 10% of women in their reproductive years, remains poorly understood. Both individual and environmental unexplained factors are implicated in this heterogenous condition. This study aims to examine the influence of a Western diet on endometriosis lesion development in mice and to uncover the mechanisms involved.

METHODS

Mice were fed either a control diet or a Western diet (high in fatty acids and low in fiber) for 4 weeks. Endometriosis was then surgically induced, and lesion development was monitored by ultrasound. After 7 weeks, the mice were sacrificed for analysis of lesion characteristics through RT-qPCR, immunohistochemistry, and flow cytometry. Additionally, the intestinal microbiota was assessed using 16S rRNA gene sequencing.

RESULTS

Mice on the Western diet developed lesions that were significantly twice as large compared to those on the control diet. These lesions exhibited greater fibrosis and proliferation, alongside enhanced macrophage activity and leptin pathway expression. Changes in the intestinal microbiota were significantly noted after endometriosis induction, regardless of diet. Notably, mice on the Western diet with the most substantial lesions showed a loss of Akkermansia Muciniphila in their intestinal microbiota.

CONCLUSIONS

A Western diet significantly exacerbates lesion size in a mouse model of endometriosis, accompanied by metabolic and immune alterations. The onset of endometriosis also leads to substantial shifts in intestinal microbiota, suggesting a potential link between diet, intestinal health, and endometriosis development.

A functional 3D full-thickness model for comprehending the interaction between airway epithelium and connective tissue in cystic fibrosis

Patients with cystic fibrosis (CF) experience severe lung disease, including persistent infections, inflammation, and irreversible fibrotic remodeling of the airways. Although therapy with transmembrane conductance regulator (CFTR) protein modulators reached optimal results in terms of CFTR rescue, lung transplant remains the best line of care for patients in an advanced stage of CF. Indeed, chronic inflammation and tissue remodeling still represent stumbling blocks during treatment, and underlying mechanisms are still unclear. Nowadays, animal models are not able to fully replicate clinical features of the human disease and the conventional in vitro models lack a stromal compartment undergoing fibrotic remodeling. To address this gap, we show the development of a 3D full-thickness model of CF with a human bronchial epithelium differentiated on a connective airway tissue. We demonstrated that the epithelial cells not only underwent mucociliary differentiation but also migrated in the connective tissue and formed gland-like structures. The presence of the connective tissue stimulated the pro-inflammatory behaviour of the epithelium, which activated the fibroblasts embedded into their own extracellular matrix (ECM). By varying the composition of the model with CF epithelial cells and a CF or healthy connective tissue, it was possible to replicate different moments of CF disease, as demonstrated by the differences in the transcriptome of the CF epithelium in the different conditions. The possibility to faithfully represent the crosstalk between epithelial and connective in CF through the full thickness model, along with inflammation and stromal activation, makes the model suitable to better understand mechanisms of disease genesis, progression, and response to therapy.

DNA methylation profiles of ovarian cysts resemble ovarian tissues but not endometrial tissues

INTRODUCTION

Endometriosis is a heritable, complex chronic inflammatory disease, for which much of the causal pathogenic mechanism remain unknown.Despite the high prevalence of ovarian chocolate cyst, its origin is still under debate.

METHODS

Prevailing retrograde menstruation model predicts that ectopic endometrial cells migrate and develop into ovarian chocolate cyst. However, other models were also proposed. Genome-wide association studies (GWASs) have proved successful in identifying common genetic variants of moderate effects for various complex diseases.

RESULTS

A growing body of evidence shows that the remodeling of retrograde endometrial tissues to the ectopic endometriotic lesions involves multiple epigenetic alterations, such as DNA methylation, histone modification, and microRNA expression.Because DNA methylation states exhibit a tissue specific pattern, we profiled the DNA methylation for ovarian cysts and paired eutopic endometrial and ovarian tissues from four patients. Surprisingly, DNA methylation profiles showed the ovarian cysts were closely grouped with normal ovarian but not endometrial tissues.

CONCLUSIONS

These results suggested alterative origin of ovarian cysts or strong epigenetic reprogramming of infiltrating endometrial cells after seeding the ovarian tissue. The data provide contributing to the pathogenesis and pathophysiology of endometriosis.

Progesterone-independent endometrial mRNA expression in dairy cows with clinical or subclinical endometritis

Up to 50 % of dairy cows fail to resolve uterine involution and develop chronic clinical (CE) or subclinical endometritis (SE) 21 days after calving. Clinical endometritis is associated with purulent discharge, while SE is not associated with overt clinical signs. Along with numerous knowledge gaps related to its pathogenesis, SE does not allow for a straightforward and effective therapy. Therefore, it is crucial to unravel differences in the expression of genes among healthy, CE, and SE cows. This might contribute to the discovery of new drug candidates and, in consequence, a potentially effective treatment. In the present study, cows between 21 and 28 days postpartum (PP) were examined using vaginoscopy for the presence of vaginal discharge and endometrial cytology for the determination of the endometrial polymorphonuclear cell (PMN) percentage. Next, an endometrial biopsy sample was taken to investigate the expression of 13 selected candidate genes by qPCR. Uterine health status was assigned to healthy (absence of abnormal vaginal discharge and ≤5 % PMN, n = 13), SE (absence of abnormal vaginal discharge and >5 % PMN, n = 30), and CE (mucopurulent or purulent vaginal discharge and >5 % PMN, n = 9). At the same time, a blood sample was collected to assess serum progesterone concentration and to categorize cows as low (≤1 ng/mL) or high (>1 ng/mL) in progesterone. High expression of IL1B, IL6, IL17A, CXCL8, PTGES, PTGS1, PTGS2, and INHBA genes and low expression of FST was noted in the endometrium of CE compared to healthy cows. Increased endometrial INHBA expression was observed in both SE and CE compared to healthy cows. Interestingly, greater expression of PTGES and PRXL2B genes and lower expression of PTGS2 were characteristic of SE versus CE or healthy. Among cows with no overt clinical symptoms of uterine disease (healthy and SE), the endometrial expression of IL1 B, CXCL8, and PTGES was greater in cows with high versus low serum progesterone. Several genes were differentially expressed among healthy, SE, and CE cows indicating different pathways for the development of different uterine diseases. In conclusion, we found progesterone-independent SE markers, which suggests that low endometrial PTGS2 expression may be indicative of an inadequate immune response and thus contribute to the pathogenesis of SE.

Galectin-3 promotes fibrosis in ovarian endometriosis

Objective

This study aimed to investigate the potential role of galectin-3 (Gal-3) in the pathogenesis of fibrotic alterations in ovarian endometriosis (OVE).

Methods

In this study, we collected the ectopic endometrial tissues and eutopic endometrial tissues from 31 OVE patients treated by laparoscopy, and the eutopic endometrial tissues from 23 non-OVE patients with leiomyoma or other benign diseases were used as control. Hematoxylin and eosin (H&E) and Masson's trichrome staining were utilized for histopathological assessment. The primary normal endometrial stromal cells (NESC), ectopic endometrial stromal cells (ECSC), and eutopic endometrial stromal cells (EUSC) were isolated. Gal-3 overexpression plasmids (Gal-OE) and short hairpin RNA targeting Gal-3 (Gal-3-shRNA) were transfected into the immortalized human endometriotic cell line 12Z, respectively. RT-qPCR, Western blot analysis, and immunohistochemistry were used to detect the mRNA and protein expression levels of Gal-3, type I collagen (COL-1), connective tissue growth factor (CTGF) and α-smooth muscle actin (α-SMA), respectively.

Results

H&E and Masson staining showed that ovarian ectopic endometrium exhibited glandular hyperplasia, high columnar glandular epithelium, apical plasma secretion, more subnuclear vacuoles, and obvious fibrosis, compared with normal endometrium. The mRNA and protein levels of Gal-3 , CTGF, α-SMA, and COL-1 were all upregulated in the ectopic endometrial tissues of OVE patients compared to the eutopic endometrial tissues from OVE patients and non-OVE patients. Moreover, ECSC expressed higher levels of Gal-3, CTGF, α-SMA, and COL-1 than EUSC and NESC. Follow-up investigations demonstrated that the Gal-3 overexpression substantially increased fibrosis-related markers including CTGF, α-SMA, and COL-1 within the 12Z cell line. Conversely, Gal-3 knockdown showed the opposite effects.

Conclusion

Gal-3 promotes fibrosis in OVE, positioning it as a prospective therapeutic target for mitigating fibrosis in endometriosis.

An integrated multi-tissue approach for endometriosis candidate biomarkers: a systematic review

Biomarker identification could help in deciphering endometriosis pathophysiology in addition to their use in the development of non invasive diagnostic and prognostic approaches, that are essential to greatly improve patient care. Despite extensive efforts, no single potential biomarker or combination has been clinically validated for endometriosis.Many studies have investigated endometriosis-associated biological markers in specific tissues, but an integrative approach across tissues is lacking. The aim of this review is to propose a comprehensive overview of identified biomarkers based on tissue or biological compartment, while taking into account endometriosis phenotypes (superficial, ovarian or deep, or rASRM stages), menstrual cycle phases, treatments and symptoms.We searched PubMed and Embase databases for articles matching the following criteria: 'endometriosis' present in the title and the associated term 'biomarkers' found as Medical Subject Headings (MeSH) terms or in all fields. We restricted to publications in English and on human populations. Relevant articles published between 01 January 2005 (when endometriosis phenotypes start to be described in papers) and 01 September 2022 were critically analysed and discussed.Four hundred forty seven articles on endometriosis biomarkers that included a control group without endometriosis and provided specific information on endometriosis phenotypes are included in this review. Presence of information or adjustment controlling for menstrual cycle phase, symptoms and treatments is highlighted, and the results are further summarized by biological compartment. The 9 biological compartments studied for endometriosis biomarker research are in order of frequency: peripheral blood, eutopic endometrium, peritoneal fluid, ovaries, urine, menstrual blood, saliva, feces and cervical mucus. Adjustments of results on disease phenotypes, cycle phases, treatments and symptoms are present in 70%, 29%, 3% and 6% of selected articles, respectively. A total of 1107 biomarkers were identified in these biological compartments. Of these, 74 were found in several biological compartments by at least two independent research teams and only 4 (TNF-a, MMP-9, TIMP-1 and miR-451) are detected in at least 3 tissues with cohorts of 30 women or more.Integrative analysis is a crucial step to highlight potential pitfalls behind the lack of success in the search for clinically relevant endometriosis biomarkers, and to illuminate the physiopathology of this disease.

Endometriosis and the Role of Pro-Inflammatory and Anti-Inflammatory Cytokines in Pathophysiology: A Narrative Review of the Literature

Endometriosis is a chronic inflammatory disease, which explains the pain that such patients report. Currently, we are faced with ineffective, non-invasive diagnostic methods and treatments that come with multiple side effects and high recurrence rates for both the disease and pain. These are the reasons why we are exploring the possibility of the involvement of pro-inflammatory and anti-inflammatory molecules in the process of the appearance of endometriosis. Cytokines play an important role in the progression of endometriosis, influencing cell proliferation and differentiation. Pro-inflammatory molecules are found in intrafollicular fluid. They have an impact on the number of mature and optimal-quality oocytes. Endometriosis affects fertility, and the involvement of endometriosis in embryo transfer during in vitro fertilization (IVF) is being investigated in several studies. Furthermore, the reciprocal influence between anti-inflammatory and pro-inflammatory cytokines and their role in the pathogenesis of endometriosis has been assessed. Today, we can affirm that pro-inflammatory and anti-inflammatory cytokines play roles in survival, growth, differentiation, invasion, angiogenesis, and immune escape, which provides a perspective for approaching future clinical implications and can be used as biomarkers or therapy.

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.

PIM2 Promotes the Development of Ovarian Endometriosis by Enhancing Glycolysis and Fibrosis

Endometriosis is a common gynecological disorder characterized by the presence of the endometrial glands and the stroma outside the uterine cavity. The disease affects reproductive function and quality of life in women of reproductive age. Endometriosis is similar to tumors in some characteristics, such as glycolysis. PIM2 can promote the development of tumors, but the mechanism of PIM2 in endometriosis is still unclear. Therefore, our goal is to study the mechanism of PIM2 in endometriosis. Through immunohistochemistry, we found PIM2, HK2, PKM2, SMH (smooth muscle myosin heavy chain), Desmin, and α-SMA (α-smooth muscle actin) were strongly expressed in the ovarian endometriosis. In endometriotic cells, PIM2 enhanced glycolysis and fibrosis via upregulating the expression of PKM2. Moreover, the PIM2 inhibitor SMI-4a inhibited the development of endometriosis. And we established a PIM2 knockout mouse model of endometriosis to demonstrate the role of PIM2 in vivo. In summary, our study indicates that PIM2 promotes the development of endometriosis. PIM2 may serve as a promising therapeutic target for endometriosis.

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

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

MicroRNA-92a-3p Inhibits Cell Proliferation and Invasion by Regulating the Transcription Factor 21/Steroidogenic Factor 1 Axis in Endometriosis

Endometriosis (EMS) is an estrogen-dependent disease. However, little is known about the regulation of estrogen, a potential therapeutic target, in EMS, which remains very poorly managed in the clinic. We hypothesized that microRNAs (miRNAs) can be exploited therapeutically to regulate transcription factor 21 (TCF21) and steroidogenic factor-1 (SF-1) gene expression. In our study, paired eutopic and ectopic endometrial samples were obtained from women with EMS and processed by a standard protocol to obtain human endometrial stromal cells (EMs) for in vitro studies. We found that miR-92a-3p levels were decreased in ectopic endometrium and ectopic stromal cells (ESCs) compared with paired eutopic lesions. miR-92a-3p overexpression significantly suppressed the proliferation and migration of ESCs, whereas a decreased level of miR-92a-3p generated the opposite results. Next, we identified TCF21 as a candidate target gene of miR-92a-3p. In vitro cell experiments showed that miR-92a-3p negatively regulated the expression of TCF21 and its downstream target gene SF-1. Moreover, cell proliferation and invasion ability decreased after the silencing of SF-1 and increased after SF-1 overexpression. We also observed that silencing SF-1 while inhibiting miR-92a-3p partially blocked the increase in cell proliferation and invasion ability caused by miR-92a-3p knockdown while overexpressing both SF-1 and miR-92a-3p mitigated the impairment in cell proliferation and invasion ability caused by miR-92a-3p overexpression. Our results may provide a novel potential therapeutic target for the treatment of EMS.

Upregulated Ribosomal Pathway Impairs Follicle Development in a Polycystic Ovary Syndrome Mouse Model: Differential Gene Expression Analysis of Oocytes

Polycystic ovary syndrome (PCOS), a common endocrine disorder, is associated with impaired oocyte development, leading to infertility. However, the pathogenesis of PCOS has not been completely elucidated. This study aimed to determine the differentially expressed genes (DEGs) and epigenetic changes in the oocytes from a PCOS mouse model to identify the etiological factors. RNA-sequencing analysis revealed that 90 DEGs were upregulated and 27 DEGs were downregulated in mice with PCOS compared with control mice. DNA methylation analysis revealed 30 hypomethylated and 10 hypermethylated regions in the PCOS group. However, the DNA methylation status did not correlate with differential gene expression. The pathway enrichment analysis revealed that five DEGs (Rps21, Rpl36, Rpl36a, Rpl37a, and Rpl22l1) were enriched in ribosome-related pathways in the oocytes of mice with PCOS, and the immunohistochemical analysis revealed significantly upregulated expression levels of Rps21 and Rpl36. These results suggest that differential gene expression in the oocytes of mice in PCOS is related to impaired folliculogenesis. These findings improve our understanding of PCOS pathogenesis.

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

Background

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

Methods

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

Results

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

Conclusions

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

IL-22 regulates endometrial regeneration by enhancing tight junctions and orchestrating extracellular matrix

The uterine endometrium uniquely regenerates after menses, postpartum, or after breaks in the uterine layer integrity throughout women’s lives. Direct cell–cell contacts ensured by tight and adherens junctions play an important role in endometrial integrity. Any changes in these junctions can alter the endometrial permeability of the uterus and have an impact on the regeneration of uterine layers. Interleukin 22 (IL-22) is a cytokine that is recognized for its role in epithelial regeneration. Moreover, it is crucial in controlling the inflammatory response in mucosal tissues. Here, we studied the role of IL-22 in endometrial recovery after inflammation-triggered abortion. Fecundity of mice was studied in consecutive matings of the same animals after lipopolysaccharide (LPS) (10 µg per mouse)-triggered abortion. The fecundity rate after the second mating was substantially different between IL-22 knockout (IL-22^−/−) (9.1%) and wild-type (WT) (71.4%) mice (p < 0.05), while there was no difference between the groups in the initial mating, suggesting that IL-22 deficiency might be associated with secondary infertility. A considerable difference was observed between IL-22^−/− and WT mice in the uterine clearance following LPS-triggered abortion. Gross examination of the uteri of IL-22^−/− mice revealed non-viable fetuses retained inside the horns (delayed clearance). In contrast, all WT mice had completed abortion with total clearance after LPS exposure. We also discovered that IL-22 deficiency is associated with a decreased expression of tight junctions (claudin-2 and claudin-10) and cell surface pathogen protectors (mucin-1). Moreover, IL-22 has a role in the remodeling of the uterine tissue in the inflammatory environment by regulating epithelial–mesenchymal transition markers called E- and N-cadherin. Therefore, IL-22 contributes to the proper regeneration of endometrial layers after inflammation-triggered abortion. Thus, it might have a practical significance to be utilized as a treatment option postpartum (enhanced regeneration function) and in secondary infertility caused by inflammation (enhanced barrier/protector function).

Fibroblast growth factor receptor 2 promotes the proliferation, migration, and invasion of ectopic stromal cells via activation of extracellular-signal-regulated kinase signaling pathway in endometriosis

Endometriosis is defined as the presence of endometrial tissues with cancer-like features in extrauterine locations. Fibroblast growth factor receptor 2 (FGFR2) is a tyrosine kinase that is involved in cancer pathogenesis. This study aimed to determine the role of FGFR2 in endometriosis. A total of 29 pairs of ectopic and eutopic endometrial tissues were collected from women with endometriosis. Endometrial tissues from women with hysteromyomas were considered as normal controls. Primary ectopic stromal cells (ESCs) were isolated from the ectopic endometrium. The role of FGFR2 in ESCs was assessed using immunohistochemistry, polymerase chain reaction, cell counting kit-8 assay, EdU staining, flow cytometry, transwell assay, and western blotting. The following signaling pathways were detected using bioinformatic analysis and confirmed in vitro. By searching the GSE171154, GSE86543, and GSE77182 datasets, FGFR2 was identified as an upregulated overlapping gene in endometriosis. Compared to eutopic and normal endometria, FGFR2 was highly expressed in ectopic tissues. Transfection of primary ESCs with FGFR2 small interfering RNA (siRNA) repressed the viability and proliferation of cells and induced apoptosis. FGFR2 siRNA inhibited the migration, invasion, and transforming growth factor-β1-triggered epithelial-mesenchymal transition (EMT). Extracellular signal-regulated kinase (ERK) signaling was found to be a downstream signaling pathway for FGFR2. The ERK1/2 inhibitor PD98059 was found to reverse the promoting effects of FGFR2 on ESC proliferation and invasion. FGFR2 silencing effectively inhibited the growth, migration, invasion, and EMT of ESCs. The effects of FGFR2 on endometriosis might be mediated via the activation of ERK signaling.

Increased serum LOXL2 concentration in pelvic inflammatory disease with pelvic adhesion

Background

Lysyl oxidase-like 2 (LOXL2) belongs to a family of the LOX secretory enzyme, which involves the cross-linkage of extracellular matrix (ECM) proteins. Here, we aimed to analyze the correlation between serum LOXL2 and pelvic adhesion in chronic pelvic inflammatory disease (PID).

Methods

A total of 143 patients with PID and 130 healthy controls were included in this study. The serum levels of LOXL2 were measured using enzyme-linked immunosorbent assay (ELISA) kits. The patients were divided into non-adhesion group (102 cases) and adhesion group (41 cases).

Results

It was found that the serum level of LOXL2 expression was elevated in PID patients compared with healthy controls, and was elevated in PID patients with pelvic adhesion compared to patients without adhesion. In all PID patients, serum LOXL2 level was positively correlated with matrix metalloproteinases-9 (MMP-9), transforming growth factor-β (TGF-β1), whole blood viscosity (WBV) at low shear rate (LSR), WBV at high shear rate (HSR), and hematocrit (HcT). Multivariate logistic regression analysis showed that serum LOXL2 level was an independent risk factor for pelvic adhesion in PID patients (OR = 1.058; 95% CI = 1.030–1.086, P < 0.001).

Conclusions

Serum LOXL2 level not only predicts the presence of PID, but serum LOXL2 concentration is also associated with the presence of pelvic adhesions.

Upregulated Fibulin-1 Increased Endometrial Stromal Cell Viability and Migration by Repressing EFEMP1-Dependent Ferroptosis in Endometriosis

Endometriosis (EMS) is a prevalent disease in women characterized by the presence of endometrial stroma and glands outside the uterus. Recent studies have showed that EMS is correlated with the resistance of endometrial stromal cells (ESCs) to ferroptosis, an iron-dependent nonapoptotic cell death. Fibulin-1 (FBLN1) is a newly identified target regulated by progesterone in the process of ESC decidualization. However, the role of FBLN1 in regulating ESC ferroptosis and EMS remains unclear. In the present study, the gene expression profiles of GSE58178, GSE23339, and GSE25628 were downloaded from the Gene Expression Omnibus (GEO) database, and the commonly differential genes were identified using Venn diagram analysis. The role of FBLN1 in ESC viability and migration was evaluated using Cell Counting Kit-8, transwell, and western blot analysis. We found that the FBLN1 expression was increased significantly in eutopic and ectopic endometrial tissues of patients with EMS compared with normal endometrium. FBLN1 overexpression in normal ESCs (NESCs) promoted cell viability and migration, whereas FBLN1 inhibition in ectopic ESCs (EESCs) decreased cell viability and migration. Furthermore, FBLN1 inhibition facilitated EESC death by triggering ferroptosis, as evidenced by increased Fe2+, lipid ROS, and malondialdehyde (MDA) level and decreased glutathione peroxidase 4 (GPX4) expression and glutathione (GSH) level. Mechanistically, FBLN1 interacted with EGF-containing fibulin-like extracellular matrix protein 1 (EFEMP1) and increased the protein stability of EFEMP1. More importantly, EFEMP1 silencing repressed the effect of FBLN1 on regulating EESC ferroptosis, death, and migration. Taken together, these results verify the role of the FBLN1/EFEMP1/ferroptosis pathway in the pathogenesis of EMS, and silencing of FBLN1/EFEMP1 might be an effective approach to treat EMS.

All-trans retinoic acid regulating angiopoietins-1 and alleviating extracellular matrix accumulation in interstitial fibrosis rats

All-trans retinoic acid (ATRA) is one of essentially active metabolite of vitamin A, and plays an important role in diverse physiological processes, such as cellular growth and function. Renal interstitial fibrosis (RIF) is a common pathological characteristic of chronic renal disease causing end-stage renal disease currently lacking effective treatment. Low level of Angiopoietins-1 (Angpt-1) is associated with extracellular matrix accumulation and fibrosis diseases. This study was performed to assess the association of ATRA with Angpt-1 in RIF disease. Rats were divided into three groups: group of sham (SHO group), group of unilateral ureteral obstruction group (UUO group), UUO mice administrated daily at the dose of ATRA (ATRA group). Masson-staining was used to detect the histologic lesion. Immunohistochemistry and Western-blot were applied to determine the targeted proteins. RIF score was significantly increased in UUO rats when compared with that of SHO group, and the fibrosis score was notably reduced in ATRA group. Transforming growth factor-β1 (TGF-β1), collagen IV (Col-IV) and fibronectin (FN) expressions in UUO group were significantly up-regulated, whereas Angpt-1 expression was significantly down-regulated compared with the SHO group. ATRA treatment reduced TGF-β1, Col-IV and FN expressions and improved Angpt-1 expression compared with the UUO group. The protein expression of Angpt-1 in kidney tissue of UUO group was negatively correlated with RIF index and protein expressions of Col-IV, FN and TGF-β1. In conclusion, low expression of Angpt-1 was associated with the RIF disease and ATRA treatment can increase the Angpt-1 and alleviate the RIF lesion in UUO rats.

New Therapeutics in Endometriosis: A Review of Hormonal, Non-Hormonal, and Non-Coding RNA Treatments

Endometriosis is defined as endometrial-like tissue outside the uterine cavity. It is a chronic inflammatory estrogen-dependent disease causing pain and infertility in about 10% of women of reproductive age. Treatment nowadays consists of medical and surgical therapies. Medical treatments are based on painkillers and hormonal treatments. To date, none of the medical treatments have been able to cure the disease and symptoms recur as soon as the medication is stopped. The development of new biomedical targets, aiming at the cellular and molecular mechanisms responsible for endometriosis, is needed. This article summarizes the most recent medications under investigation in endometriosis treatment with an emphasis on non-coding RNAs that are emerging as key players in several human diseases, including cancer and endometriosis.

Increased SUMOylation of TCF21 improves its stability and function in human endometriotic stromal cells†

Endometriosis is an estrogen-dependent disease. Our previous study demonstrated that elevated levels of transcription factor 21 (TCF21) in endometriotic tissues enhanced steroidogenic factor-1 (SF-1) and estrogen receptor β (ERβ) expression by forming a heterodimer with upstream stimulatory factor 2 (USF2), allowing these TCF21/USF2 complexes to bind to the promoters of SF-1 and ERβ. Furthermore, TCF21 contributed to the increased proliferation of endometriotic stromal cells (ESCs), suggesting that TCF21 may play a vital role in the pathogenesis of endometriosis. SUMOylation is a posttranslational modification that has emerged as a crucial molecular regulatory mechanism. However, the mechanism regulating TCF21 SUMOylation in endometriosis is incompletely characterized. Thus, this study aimed to explore the effect of TCF21 SUMOylation on its expression and regulation in ovarian endometriosis. We found that the levels of SUMOylated TCF21 were increased in endometriotic tissues and stromal cells compared with eutopic endometrial tissues and stromal cells and enhanced by estrogen. Treatment with the SUMOylation inhibitor ginkgolic acid and the results of a protein half-life assay demonstrated that SUMOylation can stabilize the TCF21 protein. A coimmunoprecipitation assay showed that SUMOylation probably increased its interaction with USF2. Further analyses elucidated that SUMOylation of TCF21 significantly increased the binding activity of USF2 to the SF-1 and ERβ promoters. Moreover, the SUMOylation motifs in TCF21 affected the proliferation ability of ESCs. The results of this study suggest that SUMOylation plays a critical role in mediating the high expression of TCF21 in ESCs and may participate in the development of endometriosis.

Impact of Sustained Transforming Growth Factor-β Receptor Inhibition on Chromatin Accessibility and Gene Expression in Cultured Human Endometrial MSC

Endometrial mesenchymal stem cells (eMSC) drive the extraordinary regenerative capacity of the human endometrium. Clinical application of eMSC for therapeutic purposes is hampered by spontaneous differentiation and cellular senescence upon large-scale expansion in vitro. A83-01, a selective transforming growth factor-β receptor (TGFβ-R) inhibitor, promotes expansion of eMSC in culture by blocking differentiation and senescence, but the underlying mechanisms are incompletely understood. In this study, we combined RNA-seq and ATAC-seq to study the impact of sustained TGFβ-R inhibition on gene expression and chromatin architecture of eMSC. Treatment of primary eMSC with A83-01 for 5 weeks resulted in differential expression of 1,463 genes. Gene ontology analysis showed enrichment of genes implicated in cell growth whereas extracellular matrix genes and genes involved in cell fate commitment were downregulated. ATAC-seq analysis demonstrated that sustained TGFβ-R inhibition results in opening and closure of 3,555 and 2,412 chromatin loci, respectively. Motif analysis revealed marked enrichment of retinoic acid receptor (RAR) binding sites, which was paralleled by the induction of RARB, encoding retinoic acid receptor beta (RARβ). Selective RARβ inhibition attenuated proliferation and clonogenicity of A83-01 treated eMSC. Taken together, our study provides new insights into the gene networks and genome-wide chromatin changes that underpin maintenance of an undifferentiated phenotype of eMSC in prolonged culture.

Vascular Homeostasis and Inflammation in Health and Disease-Lessons from Single Cell Technologies

The vascular system is critical infrastructure that transports oxygen and nutrients around the body, and dynamically adapts its function to an array of environmental changes. To fulfil the demands of diverse organs, each with unique functions and requirements, the vascular system displays vast regional heterogeneity as well as specialized cell types. Our understanding of the heterogeneity of vascular cells and the molecular mechanisms that regulate their function is beginning to benefit greatly from the rapid development of single cell technologies. Recent studies have started to analyze and map vascular beds in a range of organs in healthy and diseased states at single cell resolution. The current review focuses on recent biological insights on the vascular system garnered from single cell analyses. We cover the themes of vascular heterogeneity, phenotypic plasticity of vascular cells in pathologies such as atherosclerosis and cardiovascular disease, as well as the contribution of defective microvasculature to the development of neurodegenerative disorders such as Alzheimer's disease. Further adaptation of single cell technologies to study the vascular system will be pivotal in uncovering the mechanisms that drive the array of diseases underpinned by vascular dysfunction.