Parthenolide reduces cell proliferation and prostaglandin E2 [corrected] in human endometriotic stromal cells and inhibits development of endometriosis in the murine model

Role of tenascin C in lesion formation in early peritoneal endometriosis

OBJECTIVE

To identify cytokines or extracellular matrix components that contribute to adhesion to, and invasion of, the peritoneum, proximal to lesions in the early phase of endometriosis.

DESIGN

Laboratory-based study.

SETTING

University Hospital and Laboratory of Animal Science.

PATIENTS AND ANIMALS

Five women with ovarian endometrioma, 138 wild-type (WT) C57BL/6N mice, and 48 Tenascin C (Tnc) knockout (TncKO) mice.

INTERVENTIONS

To establish a murine endometriosis model, 20 pieces of minced uterine tissue fragments from each horn were administered intraperitoneally to syngeneic mice. Three days later, endometriotic lesions and peritoneal tissues were collected. Separately, we transfected human peritoneal mesothelial cells (HMrSV5) or human endometrial stromal cells (hESCs) with Tnc small interfering ribonucleic acid.

MAIN OUTCOME MEASURES

We employed a polymerase chain reaction array to profile gene expression in the murine peritoneum, in both peritoneum distal to lesions and peritoneum surrounding lesions (PSL). The expression of upregulated genes in the PSL was verified in the peritoneal samples by real-time reverse transcription-polymerase chain reaction. TncKO mice were used to investigate the role of Tnc in the development of endometriosis. We evaluated the proliferative activity or inflammatory state of lesions by Ki67 or CD3 immunostaining. Intraperitoneal distribution of macrophages was assessed by fluorescence-activated cell sorting. Using Tnc small interfering ribonucleic acid, we examined the invasive capacity of hESCs in a coculture system with HMrSV5.

RESULTS

Tnc gene expression was significantly higher in PSL than in peritoneum distal to lesions. The weight and number of TncKO lesions in TncKO hosts were lower than those of WT lesions in WT hosts. In contrast, the weight and number of nonattached TncKO lesions in TncKO hosts were higher than those of nonattached WT lesions in WT hosts. We observed decreased Ki67-positive cells or H-scores for CD3, a lower proportion of M1 macrophages, and a higher proportion of M2 macrophages in TncKO lesions in TncKO recipients. Silencing of Tnc expression in hESCs and HMrSV5 diminished the invasivity of hESCs.

CONCLUSION

Tnc may be a crucial factor in the development of early peritoneal endometriosis.

Trends in parthenolide research over the past two decades: A bibliometric analysis

Parthenolide (PTL) is a new compound extracted from traditional Chinese medicine. In recent years, it has been proven to play an undeniable role in tumors, autoimmune diseases, and inflammatory diseases. Similarly, an increasing number of experiments have also confirmed the biological mechanism of PTL in these diseases. In order to better understand the development trend and potential hot spots of PTL in cancer and other diseases, we conducted a detailed bibliometric analysis. The purpose of presenting this bibliometric analysis was to highlight and inform researchers of the important research directions, co-occurrence relationships and research status in this field. Publications related to PTL research from 2002 to 2022 were extracted on the web of science core collection (WoSCC) platform. CiteSpace, VOSviewers and R package "bibliometrix" were applied to build relevant network diagrams. The bibliometric analysis was presented in terms of performance analysis (including publication statistics, top publishing countries, top publishing institutions, publishing journals and co-cited journals, authors and co-cited authors, co-cited references statistics, citation bursts statistics, keyword statistics and trend topic statistics) and science mapping (including citations by country, citations by institution, citations by journal, citations by author, co-citation analysis, and keyword co-occurrence). The detailed discussion of the results explained the focus and latest trends from the bibliometric analysis. Finally, the current status and shortcomings of the research field on PTLwere clearly pointed out for reference by scholars.

CXC chemokines influence immune surveillance in immunological disorders: Polycystic ovary syndrome and endometriosis

Reproductive health is a worldwide challenge, but it is of particular significance to women during their reproductive age. Several female reproductive problems, including polycystic ovary syndrome (PCOS) and endometriosis, affect about 10 % of women and have a negative impact on their health, fertility, and quality of life. Small, chemotactic, and secreted cytokines are CXC chemokines. Both PCOS and endometriosis demonstrate dysregulation of CXC chemokines, which are critical to the development and progression of both diseases. Recent research has shown that both in humans and animals, CXC chemokines tend to cause inflammation. It has also been found that CXC chemokines are necessary for promoting angiogenesis and inflammatory responses. CXC chemokine overexpression is frequently associated with poor survival and prognosis. CXC chemokine levels in PCOS and endometriosis patients impact their circumstances significantly. Hence, CXC chemokines have significant potential as diagnostic and prognostic biomarkers and therapeutic targets. The molecular mechanisms through which CXC chemokines promote inflammation and the development of PCOS and endometriosis are currently unknown. This article will discuss the functions of CXC chemokines in the promotion, development, and therapy of PCOS and endometriosis, as well as future research directions. The current state and future prospects of CXC chemokine -based therapeutic strategies in the management of PCOS and endometriosis are also highlighted.

The therapeutic effect and mechanism of parthenolide in skeletal disease, cancers, and cytokine storm

Parthenolide (PTL or PAR) was first isolated from Magnolia grandiflora and identified as a small molecule cancer inhibitor. PTL has the chemical structure of C15H20O3 with characteristics of sesquiterpene lactones and exhibits the biological property of inhibiting DNA biosynthesis of cancer cells. In this review, we summarise the recent research progress of medicinal PTL, including the therapeutic effects on skeletal diseases, cancers, and inflammation-induced cytokine storm. Mechanistic investigations reveal that PTL predominantly inhibits NF-κB activation and other signalling pathways, such as reactive oxygen species. As an inhibitor of NF-κB, PTL appears to inhibit several cytokines, including RANKL, TNF-α, IL-1β, together with LPS induced activation of NF-κB and NF-κB -mediated specific gene expression such as IL-1β, TNF-α, COX-2, iNOS, IL-8, MCP-1, RANTES, ICAM-1, VCAM-1. It is also proposed that PTL could inhibit cytokine storms or hypercytokinemia triggered by COVID-19 via blocking the activation of NF-κB signalling. Understanding the pharmacologic properties of PTL will assist us in developing its therapeutic application for medical conditions, including arthritis, osteolysis, periodontal disease, cancers, and COVID-19-related disease.

Commonalities and Disparities between Endometriosis and Chronic Endometritis: Therapeutic Potential of Novel Antibiotic Treatment Strategy against Ectopic Endometrium

Chronic endometritis (CE) is a local mucosal inflammatory disorder of the uterine lining, which is histopathologically recognized as the unusual infiltration of CD138(+) plasmacytes into the endometrial stromal compartment. Accumulating body of research documented that CE is associated with female infertility and several obstetric/neonatal complications. The major cause of CE is thought to be intrauterine infection represented by common bacteria (Escherichia coli, Enterococcus faecalis, Streptococcus, and Staphylococcus), Mycoplasma/Ureaplasma, and Mycobacterium. Additionally, local dysbiosis in the female reproductive tract may be involved in the onset and development of CE. Antibiotic treatments against these microorganisms are effective in the elimination of endometrial stromal plasmacytes in the affected patients. Meanwhile, endometriosis is a common female reproductive tract disease characterized by endometriotic tissues (ectopic endometrium) growing outside the uterus and potentially causes chronic pelvic symptoms (dysmenorrhea, dyspareunia, dyschezia, and dysuria), infertility, and ovarian cancers. Endometriosis involves endocrinological, genetic, and epigenetic factors in its etiology and pathogenesis. Recent studies focus on immunological, inflammatory, and infectious aspects of endometriosis and demonstrate several common characteristics between endometriosis and CE. This review aimed to better understand the immunological and microbial backgrounds underlying endometriosis and CE and look into the therapeutic potential of the novel antibiotic treatment strategy against endometriosis in light of endometrial infectious disease.

Computational Systems Pharmacology and Molecular Docking Reveal an Anti-Apoptosis and Anti-Inflammatory Mechanism of Compound Angelica Ligusticum Wallichii Granules in the Treatment of Endometriosis

Background

Traditional medicine is a common treatment option for endometrioid-related symptoms. In the past few decades, Guixiong Xiaoyi formula has been widely used as a traditional medicine for the treatment of endometriosis.

Purpose

This study aimed to prepare compound Angelica Ligusticum wallichii granule (CALG) by modern technological methods and to study its pharmacodynamics and mechanisms of treating endometriosis.

Methods

The ingredients of CALG were determined by UPLC-Q-TOF/MS. Target prediction of compounds and diseases was performed using databases, and the mechanisms of CALG were predicted by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes and verified by molecular docking. Furthermore, a rat model of endometriosis was established to study the effects of CALG on endometriosis in vivo.

Results

CALG with good specificity, durability, and stability was obtained following a detailed preparation process and quality control standard. Using network systems pharmacology, 109 chemical compositions and 104 core targets were identified for the treatment of endometriosis. The composition-target-channel-disease network topology analysis of the top 15 chemical compositions of CALG showed that the beneficial effect of CALG on endometriosis was attributed to phenolic compounds. In addition, CALG treatment reduced the volume of ectopic uterine lesions, promoted apoptosis, inhibited the secretion of inflammatory cytokines, and increased HIF-1 expression in rats with endometriosis.

Conclusion

CALG induces apoptosis and inhibits inflammation and is a promising drug for the treatment of endometriosis.

An Update on the Multifaceted Role of NF-kappaB in Endometriosis

Endometriosis remains a common but challenging gynecological disease among reproductive-aged women with an unclear pathogenesis and limited therapeutic options. Numerous pieces of evidence suggest that NF-κB signaling, a major regulator of inflammatory responses, is overactive in endometriotic lesions and contributes to the onset, progression, and recurrence of endometriosis. Several factors, such as estrogen, progesterone, oxidative stress, and noncoding RNAs, can regulate NF-κB signaling in endometriosis. In the present review, we discuss the mechanisms by which these factors regulate NF-κB during endometriosis progression and provide an update on the role of NF-κB in affecting endometriotic cells, peritoneal macrophages (PMs) as well as endometriosis-related symptoms, such as pain and infertility. Furthermore, the preclinical drugs for blocking NF-κB signaling in endometriosis are summarized, including plant-derived medicines, NF-κB inhibitors, other known drugs, and the potential anti-NF-κB drugs predicted through the Drug-Gene Interaction Database. The present review discusses most of the studies concerning the multifaceted role of NF-κB signaling in endometriosis and provides a summary of NF-κB-targeted treatment in detail.

Antibiotic Therapy and Vaginal Microbiota Transplantation Reduce Endometriosis Disease Progression in Female Mice via NF-κB Signaling Pathway

Endometriosis (EMS) is a disease characterized by estrogen-dependent, chronic inflammatory, and annoying symptoms, which inflicts about 10% reproductive-age women. The diagnosis of endometriosis mainly depends on pathological examination after surgical resection while the pathogenesis of EMS is not clear enough. Surgical resection and drug therapy (including painkillers and hormone therapy, especially gonadotropin-releasing hormone analogs, GnRH-a) are widely used, but they are expensive and have many side effects. There are few studies on vaginal microorganisms in women with endometriosis. We collected vaginal secretions from women with EMS confirmed by pathology and demonstrated that they were different from that of healthy women by 16s rRNA high-throughput sequencing. Additionally, we established the EMS model in female mice by intraperitoneally injecting fragments from donor mice (3-week growth). Then, the mice were treated with mixed antibiotics (vagina) and NF-κB signaling pathway inhibitors (intraperitoneal injection), respectively. The result suggested that the ectopic lesions were inhibited. In addition, inflammatory cytokines IL-1β, IL-6, and TNF-α in peritoneal fluid, cell proliferation marker ki-67, and macrophage marker Iba-1 in ectopic lesions decreased significantly from that of mock mice. We also observed similar results as above by vaginal microbiota transplantation (VMT) and subcutaneous injection of leuprorelin acetate (LA, one of GnRH-a) for mice with EMS. These results showed that vaginal use of antibiotics or VMT is helpful to treat endometriosis in mice. However, due to the great difference between human and mouse vaginal microbiota, its mechanism and clinical transformation application still need to be further studied in the future.

Endometriosis in the Mouse: Challenges and Progress Toward a ‘Best Fit’ Murine Model

Endometriosis is a prevalent gynecologic condition associated with pelvic pain and infertility characterized by the implantation and growth of endometrial tissue displaced into the pelvis via retrograde menstruation. The mouse is a molecularly well-annotated and cost-efficient species for modeling human disease in the therapeutic discovery pipeline. However, as a non-menstrual species with a closed tubo-ovarian junction, the mouse poses inherent challenges as a preclinical model for endometriosis research. Over the past three decades, numerous murine models of endometriosis have been described with varying degrees of fidelity in recapitulating the essential pathophysiologic features of the human disease. We conducted a search of the peer-reviewed literature to identify publications describing preclinical research using a murine model of endometriosis. Each model was reviewed according to a panel of ideal model parameters founded on the current understanding of endometriosis pathophysiology. Evaluated parameters included method of transplantation, cycle phase and type of tissue transplanted, recipient immune/ovarian status, iterative schedule of transplantation, and option for longitudinal lesion assessment. Though challenges remain, more recent models have incorporated innovative technical approaches such as in vivo fluorescence imaging and novel hormonal preparations to overcome the unique challenges posed by murine anatomy and physiology. These models offer significant advantages in lesion development and readout toward a high-fidelity mouse model for translational research in endometriosis.

Preclinical models of endometriosis and interstitial cystitis/bladder pain syndrome: an Innovative Medicines Initiative-PainCare initiative to improve their value for translational research in pelvic pain

ABSTRACT

Endometriosis (ENDO) and interstitial cystitis/bladder pain syndrome (IC/BPS) are chronic pain conditions for which better treatments are urgently needed. Development of new therapies with proven clinical benefit has been slow. We have conducted a review of existing preclinical in vivo models for ENDO and IC/BPS in rodents, discussed to what extent they replicate the phenotype and pain experience of patients, as well as their relevance for translational research. In 1009 publications detailing ENDO models, 41% used autologous, 26% syngeneic, 18% xenograft, and 11% allogeneic tissue in transplantation models. Intraperitoneal injection of endometrial tissue was the subcategory with the highest construct validity score for translational research. From 1055 IC/BPS publications, most interventions were bladder centric (85%), followed by complex mechanisms (8%) and stress-induced models (7%). Within these categories, the most frequently used models were instillation of irritants (92%), autoimmune (43%), and water avoidance stress (39%), respectively. Notably, although pelvic pain is a hallmark of both conditions and a key endpoint for development of novel therapies, only a small proportion of the studies (models of ENDO: 0.5%-12% and models of IC/BPS: 20%-44%) examined endpoints associated with pain. Moreover, only 2% and 3% of publications using models of ENDO and IC/BPS investigated nonevoked pain endpoints. This analysis highlights the wide variety of models used, limiting reproducibility and translation of results. We recommend refining models so that they better reflect clinical reality, sharing protocols, and using standardized endpoints to improve reproducibility. We are addressing this in our project Innovative Medicines Initiative-PainCare/Translational Research in Pelvic Pain.

Plants as source of new therapies for endometriosis: a review of preclinical and clinical studies

BACKGROUND

Given the disadvantages and limitations of current endometriosis therapy, there is a progressive increase in studies focusing on plant-derived agents as a natural treatment option with the intention of achieving high efficiency, avoiding adverse effects and preserving the chance for successful pregnancy. The heterogeneity of these studies in terms of evaluated agents, applied approaches and outcomes illustrates the need for an up-to-date summary and critical view on this rapidly growing field in endometriosis research.

OBJECTIVE AND RATIONALE

This review provides a comprehensive overview of plant-derived agents and natural treatment strategies that are under preclinical or clinical investigation and critically evaluates their potential for future endometriosis therapy.

SEARCH METHODS

An English language PubMed literature search was performed using variations of the terms 'endometriosis', 'natural therapy', 'herb/herbal', 'plant', 'flavonoid', 'polyphenol', 'phytochemical', 'bioactive', 'Kampo' and 'Chinese medicine'. It included both animal and human studies. Moreover, the Clinicaltrials.gov database was searched with the term 'endometriosis' for clinical trials on plant-derived agents. No restriction was set for the publication date.

OUTCOMES

Natural therapies can be assigned to three categories: (i) herbal extracts, (ii) specific plant-derived bioactive compounds and (iii) Chinese herbal medicine (CHM). Agents of the first category have been shown to exert anti-proliferative, anti-inflammatory, anti-angiogenic and anti-oxidant effects on endometrial cells and endometriotic lesions. However, the existing evidence supporting their use in endometriosis therapy is quite limited. The most studied specific plant-derived bioactive compounds are resveratrol, epigallocatechin-3-gallate, curcumin, puerarin, ginsenosides, xanthohumol, 4-hydroxybenzyl alcohol, quercetin, apigenin, carnosic acid, rosmarinic acid, wogonin, baicalein, parthenolide, andrographolide and cannabinoids, with solid evidence about their inhibitory activity in experimental endometriosis models. Their mechanisms of action include pleiotropic effects on known signalling effectors: oestrogen receptor-α, cyclooxygenase-2, interleukin-1 and -6, tumour necrosis factor-α, intercellular adhesion molecule-1, vascular endothelial growth factor, nuclear factor-kappa B, matrix metalloproteinases as well as reactive oxygen species (ROS) and apoptosis-related proteins. Numerous studies suggest that treatment with CHM is a good choice for endometriosis management. Even under clinical conditions, this approach has already been shown to decrease the size of endometriotic lesions, alleviate chronic pelvic pain and reduce postoperative recurrence rates.

WIDER IMPLICATIONS

The necessity to manage endometriosis as a chronic disease highlights the importance of identifying novel and affordable long-term safety therapeutics. For this purpose, natural plant-derived agents represent promising candidates. Many of these agents exhibit a pleiotropic action profile, which simultaneously inhibits fundamental processes in the pathogenesis of endometriosis, such as proliferation, inflammation, ROS formation and angiogenesis. Hence, their inclusion into multimodal treatment concepts may essentially contribute to increase the therapeutic efficiency and reduce the side effects of future endometriosis therapy.

Phytotherapy in endometriosis: an up-to-date review

Endometriosis is a benign gynecological disease which symptoms can provide a severe impact on patient's quality of life with subsequent impact on psychological well-being. Different therapeutic strategies are available to treat this disease, such as surgery, hormonal therapies, and nonsteroidal anti-inflammatory drugs. Nevertheless, the efficacy of conventional medical treatments is limited or intermittent in most of the patients due to the associated side effects. Therefore, a woman with endometriosis often search for additional and alternative options, and phytotherapy might be a promising alternative and complementary strategy. Different medicinal plants, multicomponent herbal preparations, and phytochemicals were investigated for pharmacological proprieties in endometriosis therapy. In most of the cases, the effect on endometriosis was related to phenolic compounds, such as flavonoids and phenolic acids reporting anti-inflammatory, proapoptotic, antioxidant, and immunomodulatory functions. Moreover, some phytochemicals have been related to a strong phytoestrogenic effect modulating the estrogen activity. Although promising, available evidence is based on in vitro and animal models of endometriosis with a limited number of well-performed clinical studies. There are almost none randomized control trials in this area. Therefore, properly constructed clinical trials are mandatory to achieve more conclusive results about the promising role of phytotherapy in the management of endometriosis.

NLRC5 Inhibits Inflammation of Secretory Phase Ectopic Endometrial Stromal Cells by Up-Regulating Autophagy in Ovarian Endometriosis

Nod-like receptor (NLR) family caspase activation and recruitment domain containing 5 (NLRC5) is a newly identified sub-class of the NLR family. It regulates inflammation and has a key function in innate and adaptive immunologic reactions. Autophagy has been reported to be crucially linked to the pathogenesis of endometriosis. Our recent study identify there is a negative correlation between NLRC5 and autophagy in endometriosis, indicating that NLRC5 and autophagy together act as promising predictors in endometriosis patients. However, the mechanism associating NLRC5 and autophagy in endometriosis is still not completely understood. We hypothesize that autophagy could be involved in NLRC5-mediated inflammation in endometriosis. In order to validate the assumption, we evaluate the effects of NLRC5 and autophagy in the inflammation of ectopic endometrial stromal cells (EESCs) of ovarian endometriosis patients, to specifically determine whether autophagy is involved in NLRC5-mediated inflammation in EESCs. Our results show that over-expression of NLRC5 results in the up-regulation of autophagy in EESCs and inhibition of NLRC5 restricts the level of autophagy in EESCs. Furthermore, over-expression of NLRC5 and promotion of autophagy inhibit interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) expressions, whereas inhibition of NLRC5 and autophagy up-regulate IL-6 and TNF-α expressions in EESCs. Additionally, promotion of autophagy contributes to the NLRC5-mediated inhibition of IL-6 and TNF-α expressions in EESCs; inhibition of autophagy restricts NLRC5-mediated inhibition of IL-6 and TNF-α expressions in EESCs. Our results suggest that over-expression of NLRC5 promotes autophagy, thereby inhibiting inflammation in ovarian endometriosis.

Endometriosis: current challenges in modeling a multifactorial disease of unknown etiology

Endometriosis is a chronic inflammatory hormone-dependent condition associated with pelvic pain and infertility, characterized by the growth of ectopic endometrium outside the uterus. Given its still unknown etiology, treatments usually aim at diminishing pain and/or achieving pregnancy. Despite some progress in defining mode-of-action for drug development, the lack of reliable animal models indicates that novel approaches are required. The difficulties inherent to modeling endometriosis are related to its multifactorial nature, a condition that hinders the recreation of its pathology and the identification of clinically relevant metrics to assess drug efficacy. In this review, we report and comment endometriosis models and how they have led to new therapies. We envision a roadmap for endometriosis research, integrating Artificial Intelligence, three-dimensional cultures and organ-on-chip models as ways to achieve better understanding of physiopathological features and better tailored effective treatments.

Mental stress promotes the proliferation of endometriotic lesions in mice

Endometriosis is a condition in which tissue similar to the womb lining begins to grow in other sites, such as the ovaries or fallopian tubes. Endometriosis can cause pelvic pain, adhesion formation, and infertility. Here, we investigated the relationship between deterioration of endometriosis and inflammation of intraperitoneal adipose tissue in mice. We created a mouse model of endometriosis, then subjected these mice to stress loading. In the experimental mice, we measured protein expression levels of prostaglandin-E2, monocyte chemoattractant protein-1, and tumor necrosis factor-α using ELISA kits. We used quantitative real-time polymerase chain reaction to measure mRNA expression levels of inflammation-related enzymes and cytokines in lesions and adipose tissues. This study sugest that endometriotic lesions may progress in the presence of psychological stress in the presence of endometriosis. In addition, inflammation of the adipose tissue around the uterus may be involved in the development of endometriosis. However, this needs further consideration. Reducing or avoiding stress as much as possible may prevent the progression of endometriosis.

Endometrial stromal cells treated by tumor necrosis factor-α stimulate macrophages polarized toward M2 via interleukin-6 and monocyte chemoattractant protein-1

AIM

This study aimed to investigate the effects of endometrial stromal cells (ESC)-derived interleukin (IL)-6 and monocyte chemoattractant protein (MCP)-1 on macrophage polarization in endometriosis.

METHODS

Macrophage polarization was measured in eutopic endometrium of control participants ('normal endometrium'), eutopic endometrium of patients with endometriosis ('eutopic endometrium') and ectopic endometrium of endometriosis patients ('ectopic endometrium') by immunohistochemical staining. Expression of IL-6 and MCP-1 were measured in the eutopic and ectopic endometrium through enzyme-linked immunosorbent assays. Expression of CD163 was measured in human acute monocytic leukemia (THP-1) cell-derived macrophages that were treated with conditional medium induced by tumor necrosis factor (TNF)-α, TNF-α + anti-IL-6 or TNF-α + anti-MCP-1 via flow cytometry.

RESULTS

The ratio of CD163+/CD68+ macrophages in the normal endometrium was higher than that in the eutopic endometrium, while differences between the eutopic and ectopic endometrium were not statistically significant. IL-6 and MCP-1 exhibited enhanced expression in the ectopic endometrium group and decreased expression in the eutopic endometrium group. TNF-α could promote the expression of ESC-derived IL-6 and MCP-1. Intervention with TNF-α-induced conditioned medium resulted in the upregulation of CD163 in THP-1 cells, while conditional medium induced with IL-6 and MCP-1 neutralizing antibodies decreased the proportion of CD163+ macrophages significantly.

CONCLUSION

In endometriosis patients, the macrophages of the eutopic endometrium polarize toward M1 compared with the normal endometrium, and those of the ectopic endometrium were mainly M2-polarized. Under the action of TNF-α, ESC-derived IL-6 and MCP-1 could stimulate peritoneal macrophages toward M2-polarization, which could modulate endometriosis.

β-catenin signaling inhibitors ICG-001 and C-82 improve fibrosis in preclinical models of endometriosis

Endometriosis exhibits unique characteristics, such as fibrosis, resistance to apoptosis, and promotion of cell proliferation; however, its pathophysiology is not fully understood. Recurrence rates after treatment are high, and the progression risk continues until menopause; hence, more effective therapy for endometriosis is needed. CREB-binding protein (CBP)/β-catenin signaling inhibitors have demonstrated antifibrogenetic effects in liver, lung, and skin diseases. The present study evaluated the effects of two CBP/β-catenin signaling inhibitors, ICG-001 and C-82, on the progression of endometriosis using endometriotic cyst stromal cells from the ovary and normal endometrial stromal cells from the uterus. ICG-001 was also evaluated in a mouse model. ICG-001 and C-82 inhibited cell proliferation, fibrogenesis, and cell migration, and promoted apoptosis in vitro. ICG-001 inhibited the growth of endometriotic lesions in the mouse model. CBP/β-catenin signaling plays an important role in the pathophysiology of endometriosis. Inhibiting the CBP/β-catenin signal can be a therapeutic target for endometriosis.

Local estrogen formation and its regulation in endometriosis

BACKGROUND

It has been well established that endometriosis is an estrogen-dependent disease. Although the exact pathogenesis of the disease is still unclear, it is known to be characterized by estrogen-dependent growth and maintenance of the ectopic endometrium and increased local estrogen production.

METHODS

The authors reviewed studies on local estrogen production and estrogen activities mediated by estrogen receptors in endometriotic tissues.

MAIN FINDINGS

Aberrant expression of several enzymes in local endometriotic lesions contributed to the production and metabolism of estrogens. Aromatase was one of the key therapeutic targets for the regulation of local estrogen formation. Our findings suggest that PGC-1a, a transcriptional coactivator-modulating steroid hormone, regulates aromatase expression and activity. Estrogen activities mediated by different types of estrogen receptors abnormally elevated in local tissues could also be involved in the development of endometriosis. The authors demonstrated that the isoflavone aglycone, a partial agonist of the estrogen receptor, suppressed the formation of endometriotic lesions.

CONCLUSIONS

Local estrogen production and estrogen activity mediated by estrogen receptors are important potential therapeutic targets for endometriosis.

Tokishakuyakusan, a Kampo medicine, attenuates endometriosis-like lesions and hyperalgesia in murine with endometriosis-like symptoms

PROBLEM

How are the effects of Tokishakuyakusan (TSS), a traditional Japanese medicine (Kampo) on murine endometriosis model?

METHODS

BALB/c mice were used for making the murine endometriosis model. Homogeneous uterus was surgically implanted with lipopolysaccharide (LPS) in peritoneal cavity. We administered 2 weeks of TSS (1.0 g/kg) orally. Upon treatment completion, we performed the hot plate test for all mice and collected blood samples before sacrifice. Then, the endometriosis-like lesions and uteri in the abdominal cavity were harvested. Concentrations of several cytokines in sera and cyst fluids were measured using Bio-Plex Suspension Array System. IL-33 localization was determined by immunohistochemistry. Gene expression of inflammatory cytokines in the endometriosis-like lesions or the eutopic endometrium was evaluated by real-time RT-PCR.

RESULTS

After 14 days of TSS treatment, the numbers of endometriosis-like cysts and cyst weight were significantly decreased. In TSS-treated mice, the latency against heat stimuli was extended. Inflammatory cytokine concentrations in sera were not changed by TSS treatment. TSS intake decreased IL-33 mRNA expression in endometriosis-like lesions and led to the tendency of attenuation of the elevated IL-33 synthesis in the cyst fluids of lesions.

CONCLUSION

These results suggest the TSS ameliorated the hyperalgesia and lesion formation on the LPS-accelerated endometriosis-like model. TSS represents a possible ideal target of novel therapeutics for endometriosis patients with dysmenorrhea.

Plant-derived medicines for treatment of endometriosis: A comprehensive review of molecular mechanisms

Endometriosis is an estrogen-dependent disease with inflammatory lesions at extra-uterine sites, causing pelvic pain and fertility reduction. Conventional therapies primarily focus on reducing systemic levels of estrogens; however, they do not have desirable effectiveness and possess considerable side effects. Therefore, there is a growing interest in the use of herbal medicine for the treatment of endometriosis. In this paper, electronic databases including PubMed, Scopus, Cochrane library and Google Scholar were searched to obtain any studies evaluating any herbal products in the management of endometriosis. Data were collected from 1980 to 2018. Most of studies investigating the effect of herbal medicines in endometriosis were in vitro and animal and only three clinical trials were found; one on Pinus pinaster bark extract (Pycnogenol) and two on Chinese herbal formulas. The studies on phytochemicals had mostly focused on polyphenolic compounds (epigallocatechin-3-gallate, genistein) and sesquiterpenes (β-caryophyllene, parthenolide). Various molecular mechanisms of action have been involved in beneficial effects of herbal medicines and phytochemicals including anti-inflammatory (via reduction of proinflammatory cytokines such as interleukin -1, interleukin -6, interleukin -8, transforming growth factor-beta, tumor necrosis factor-α, nuclear factor-kappa B, growth factors, monocyte chemoattractant protein-1), antioxidant (through downregulation of hydrogen peroxide, malondialdehyde, reactive oxygen species and upregulation of superoxide dismutase), anti-proliferative and apoptotic (via enhancing Bcl-2-associated X protein/ B-cell lymphoma-2 and caspase3, 8 and 9 activity), anti-angiogenic (by downregulation of vascular endothelial growth factor receptors/ vascular endothelial growth factor), anti-invasive (via decreasing expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1 and matrix metalloproteinases), immunomodulatory, and estrogen modulating activities. So, medicinal plants seem to be a valuable source for identifying new drugs for treatment of endometriosis; however, since most of studies are preclinical, further clinical trials are required to achieve more conclusive results.

Aromatase as a target for treating endometriosis

Endometriosis is a common gynecological disease that causes various clinical symptoms, such as chronic pelvic pain, dysmenorrhea and infertility, seriously affecting women's health and their quality of life. The symptoms and endometriotic lesions are relieved, in many cases, after menopause, when estrogen levels are lowered. Therefore, endometriosis is considered to be estrogen-dependent. Aromatase, the enzyme responsible for the last step of estrogen biosynthesis converting testosterone and androgen to estrogen, was previously reported to be more abundant in endometriotic tissues than in the normal endometrium, leading to an increased local estrogen concentration. Therefore, aromatase is considered a key therapeutic target for regulating local estrogen biosynthesis in endometriosis. A more complete understanding of the mechanisms that modulate aromatase and its activity is required to develop novel estrogen-targeted therapies for endometriosis. In this review article, we outline the current understanding of the pathological processes involved in estrogen production in endometriosis and propose novel strategies to treat this disorder.

Daidzein-rich isoflavone aglycones inhibit cell growth and inflammation in endometriosis

Endometriosis is an estrogen-dependent disease, and isoflavones interact with estrogen receptors. The purposes of this study are to investigate the in vitro and in vivo effects of daidzein-rich isoflavone aglycones (DRIAs), dietary supplements, on cellular proliferation in endometriosis. Stromal cells isolated from ovarian endometrioma (OESCs) and normal endometrium (NESCs) were cultured with DRIAs, i.e., each of the DRIA components (daidzein, genistein, or glycitein), or isoflavone glycosides (IG; DRIA precursors). A mouse model of endometriosis was established by transplanting donor-mouse uterine fragments into recipient mice. Our results showed that DRIAs (0.2-20 μM) inhibited the proliferation of OESCs (P < 0.05 for 0.2 μM; P < 0.01 for 2 and 20 μM) but not of NESCs. However, daidzein, genistein, glycitein, and IG did not inhibit their proliferation. DRIA-induced suppression was reversed by inhibition of the estrogen receptor (ER)β by an antagonist, PHTPP, or by ERβ siRNA (P < 0.05), but not by MPP, an ERα antagonist. In OESCs, DRIAs led to reduced expression of IL-6, IL-8, COX-2, and aromatase, as well as reduced aromatase activity, serum glucocorticoid-regulated kinase levels, and PGE₂ levels (P < 0.05). Western blot and immunofluorescence assays revealed that DRIAs inhibited TNF-α-induced IκB phosphorylation and p65 uptake into the nuclei of OESCs. In the mouse model, a DRIA-containing feed significantly decreased the number, weight, and Ki-67 proliferative activity of endometriosis-like lesions compared to in mice fed with an IG-containing feed and the control feed (P < 0.01). In conclusion, DRIAs inhibit cellular proliferation in endometriosis, thus representing a potential therapeutic option for the management of endometriosis.

Lipopolysaccharide promotes the development of murine endometriosis-like lesions via the nuclear factor-kappa B pathway

PROBLEM

Is lipopolysaccharide (LPS) involved in the development of endometriosis?

METHOD OF STUDY

BALB/c mice (n=69) were used for the murine endometriosis model. Mice with surgically induced endometriosis were injected with LPS intraperitoneally. After 4 weeks of LPS injections with or without the nuclear factor-kappa B (NF-κB) inhibitor, the extent of endometriosis-like lesions was evaluated. Expression of inflammatory factors in the implants was evaluated using real-time RT-PCR. Cell proliferation, angiogenic activity, inflammation, and NF-κB phosphorylation were assessed by immunohistochemical staining.

RESULTS

Lipopolysaccharide increased total number, size, and mRNA expression of Ptgs-2, Vegf, Ccl-2, and Il-6 in endometriosis-like lesions. LPS also increased the percentage of Ki67-positive cells and enhanced the intensity and rate of positive cells of CD3, F4/80, and PECAM. Intense expression of phospho-NF-κB p65 after LPS administration was observed. Treatment with the NF-kB inhibitor negated these LPS-induced effects.

CONCLUSION

LPS-induced pelvic inflammation status enhanced the development of murine endometriosis-like lesions via NF-κB pathway.

Kinase signalling pathways in endometriosis: potential targets for non-hormonal therapeutics

BACKGROUND

Endometriosis, the growth of endometrial tissue outside the uterine cavity, is associated with chronic pelvic pain, subfertility and an increased risk of ovarian cancer. Current treatments include the surgical removal of the lesions or the induction of a hypoestrogenic state. However, a reappearance of the lesion after surgery is common and a hypoestrogenic state is less than optimal for women of reproductive age. Additional approaches are required. Endometriosis lesions exist in a unique microenvironment characterized by increased concentrations of hormones, inflammation, oxidative stress and iron. This environment influences cell survival through the binding of membrane receptors and a subsequent cascading activation of intracellular kinases that stimulate a cellular response. Many of these kinase signalling pathways are constitutively activated in endometriosis. These pathways are being investigated as therapeutic targets in other diseases and thus may also represent a target for endometriosis treatment.

METHODS

To identify relevant English language studies published up to 2015 on kinase signalling pathways in endometriosis, we searched the Pubmed database using the following search terms in various combinations; 'endometriosis', 'inflammation', 'oxidative stress', 'iron', 'kinase', 'NF kappa', 'mTOR', 'MAPK' 'p38', 'JNK', 'ERK' 'estrogen' and progesterone'. Further citing references were identified using the Scopus database and finally current clinical trials were searched on the clinicaltrials.gov trial registry.

RESULTS

The current literature on intracellular kinases activated by the endometriotic environment can be summarized into three main pathways that could be targeted for treatments: the canonical IKKβ/NFκB pathway, the MAPK pathways (ERK1/2, p38 and JNK) and the PI3K/AKT/mTOR pathway. A number of pharmaceutical compounds that target these pathways have been successfully trialled in in vitro and animal models of endometriosis, although they have not yet proceeded to clinical trials. The current generation of kinase inhibitors carry a potential for adverse side effects.

CONCLUSIONS

Kinase signalling pathways represent viable targets for endometriosis treatment. At present, however, further improvements in clinical efficacy and the profile of adverse effects are required before these compounds can be useful for long-term endometriosis treatment. A better understanding of the molecular activity of these kinases, including the specific extracellular compounds that lead to their activation in endometriotic cells specifically should facilitate their improvement and could potentially lead to new, non-hormonal treatments of endometriosis.

Novel agents for the medical treatment of endometriosis

PURPOSE OF REVIEW

Current medical treatments for endometriosis-associated pain, including oral contraceptives, progestins and GnRH agonists, are partially effective and have significant side-effects. The purpose of this review is to present new hormonal and nonhormonal treatment for endometriosis.

RECENT FINDINGS

At present, the ideal drug that can prevent, inhibit or stop development of endometriosis, reduce associated pain or infertility and allow conception does not exist. New drugs in development for endometriosis modulate GnRH, estrogen and/or progesterone receptors, or target endometriosis-associated inflammation, angiogenesis, adhesion and/or tissue invasion. Most have been tested in rodents, and have been evaluated in more relevant animal models like nonhuman primates (baboons), but only a few, that is GnRH antagonists, have been tested in human randomized controlled trials. Important safety and efficacy issues remain a concern, as steroid receptors, inflammation, adhesion, angiogenesis and tissue invasion are key factors in physiological events like ovulation, menstruation and embryo implantation.

SUMMARY

New drugs for the medical treatment of endometriosis targeting both hormonal (GnRH, estrogen and progesterone receptors) and nonhormonal pathways (inflammation, angiogenesis, adhesions, tissue invasion) are promising, but their efficacy and safety need to be established in randomized human trials before they can be used in clinical practice.

Inhibitor of apoptosis proteins (IAPs) may be effective therapeutic targets for treating endometriosis

STUDY QUESTION

What is the role of the inhibitor of apoptosis proteins (IAPs) in human endometriotic tissues and a mouse model of endometriosis?

SUMMARY ANSWER

Four IAP proteins were expressed in endometriotic tissue indicating IAPs may be a key factor in the pathogenesis and progression of endometriosis.

WHAT IS KNOWN ALREADY

Overexpression of IAPs protects against a number of proapoptotic stimuli. IAPs (c-IAP1, c-IAP2, XIAP and Survivin) are expressed in human ectopic endometrial stromal cells (ESCs) from ovarian endometriomas.

STUDY DESIGN, SIZE, DURATION

Forty-eight women with or without ovarian endometrioma are included in this study. BALB/c mice (n = 24) were used for the mouse endometriosis model. Mice with surgically induced endometriosis were treated with an IAP antagonist (BV6) for 4 weeks.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Human ectopic endometrial tissues from chocolate cysts and eutopic endometrial tissue were collected. ESCs were enzymatically isolated from these tissues. ESC proliferation was examined by 5-bromo-2'-deoxyuridine-enzyme-linked immunosorbent assay. IAPs expression in tissue derived from eutopic endometria and chocolate cysts was evaluated using real-time RT-PCR and immunohistochemistry. A homologous mouse endometriosis model was established by transplanting donor mouse uterine tissue into the abdominal cavities of recipient mice. After treating the mice with BV6 (i.p. 10 mg/ml), the extent of endometriosis-like lesions in mice was measured and proliferative activity assessed by Ki67 staining. All experiments were repeated a minimum of three times.

MAIN RESULTS AND THE ROLE OF CHANCE

IAP (c-IAP1, c-IAP2, XIAP and Survivin) mRNA and protein in human ectopic endometrial tissues were expressed at higher levels than in eutopic endometrial tissues (P < 0.05). All four IAPs proteins were expressed in mouse endometriosis-like implants. BV6 inhibited BrdU incorporation of human ESCs (P < 0.05 versus control). BV6 also decreased the total number, weight, surface area and Ki67 positive cells in the endometriosis-like lesions in the mice (P < 0.05 versus control).

LIMITATIONS, REASONS FOR CAUTION

Endometriotic lesions were surgically induced in mice by transplanting mouse uterine tissue only, not human pathological endometriotic tissue. Furthermore, the effects of BV6 on human ESCs and mouse endometriosis-like lesions may differ between the species.

WIDER IMPLICATIONS OF THE FINDINGS

Our data support the hypothesis that IAPs are involved in the development of endometriosis, and therefore an inhibitor of IAPs has potential as a novel treatment for endometriosis.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by KAKENHI (Japan Society for the Promotion of Science, Grant-in-Aid: to F.T.; 21592098 and to T.H.; 24659731) and Yamaguchi Endocrine Research Foundation. The authors have no conflicts of interest to disclose.

Power over Pain: A Brief Review of Current and Novel Interventions for Endometriosis-Associated Pain

An estimated 10%-15% of women of reproductive age suffer from endometriosis and can be plagued with one or many forms of pain. It is no mystery that endometriosis is an extremely complex disease, with several factors leading to the predominant symptoms of infertility and pain. Although there are currently multiple options available for treating endometriosis-associated pain, none have the ability to completely relieve the symptoms. This review both highlights the current trends in treatment of endometriosis-associated pain and explores some novel options available for therapy directed towards oxidative stress, inflammation and nociceptive mechanisms of pain. A PubMed search was conducted to identify the most recent publications on the topic of pain associated with endometriosis, and further research was performed to clarify the mechanism by which current treatments target pain. Lastly, the authors include a review of pharmacological options at the forefront of endometriosis research. A more comprehensive understanding of the mechanisms behind endometriosis-associated pain will ultimately lead to more effective treatments and improved prognoses for patients.