Aromatase expression in endometriotic tissues and cell cultures of patients with endometriosis

Endometriosis in Menopausal Women-A New Age Is Coming? Literature Review

Endometriosis is a chronic inflammatory disease, characterized by the presence of ectopic endometrial tissue, that leads to dysmenorrhea, painful intercourse and infertility. The shift in paradigm from the previous belief that endometriosis exclusively impacts women of reproductive age has brought attention to the condition in both premenarchal and postmenopausal women. Currently, 2-4% of postmenopausal women have endometriosis. Many women experience menopausal symptoms during the peri- and postmenopausal periods and require extensive investigations and monitoring in order to avoid the recurrence of endometriosis symptoms or the risk of malignant transformation when treatment with menopausal hormones is elected. Our goal was to compile and present a clear and concise overview of the existing literature on postmenopausal endometriosis, offering an up-to-date and precise summary of the available information.

Low-Nutrient Environment-Induced Changes in Inflammation, Cell Proliferation, and PGC-1α Expression in Stromal Cells with Ovarian Endometriosis

Although nutrient status plays an important role in cell metabolism, its significance in endometriosis is obscure. Herein, we investigated the effects of a low-nutrient microenvironment on endometriosis. Stromal cells (SCs) from ovarian endometrioma (OESCs) or normal endometrium without endometriosis (NESCs) were isolated and cultured. A low-nutrient microenvironment was replicated by replacing the culture medium with Hank's balanced salt solution. OESC and NESC proliferation under the low-nutrient condition was measured. The expression of exacerbating factors in endometriosis under the low-nutrient condition was examined at the mRNA and protein levels. OESCs showed higher proliferation than NESCs under the low-nutrient condition. In OESCs, the low-nutrient condition upregulated the mRNA expression of vascular endothelial growth factor (VEGF), interleukin-6 and -8, aromatase, Bcl-2, and peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) and downregulated that of BAX and induced transcription of PI.3, PII, and exon II. Western blotting revealed elevated VEGF and PGC-1α expression under the low-nutrient condition in OESCs. These changes coincided with the elevated expression of PGC-1α, which was reduced at the mRNA level upon nutrient status rescue. Endometriosis is exacerbated by altered angiogenesis, inflammation, anti-apoptosis, and local estrogen production while trying to survive under a low-nutrient microenvironment; it may be attributed to PGC-1α-mediated metabolic mechanisms.

Therapeutic effects of melatonin on endometriosis, targeting molecular pathways: Current knowledge and future perspective

Endometriosis, the very serious disease in women creates a huge financial burden worldwide, which is comparable to diabetes mellitus. In addition to the typical pelvic pain, endometriosis is related to low life quality and decreased work efficiency; clinical consequences include mood complaints, metabolic impairments, inflammation, immunologic problems, and elevated malignancy risks. Several risk factors are correlated with endometriosis including elevated oxidative and nitrosative stress, long-lasting inflammation, raised immune tolerance, as well as autoimmunity. Melatonin is a natural molecule present throughout both the plant and animal kingdoms. It has numerous functions as an antioxidant and anti-inflammatory agent. Due to the anti-proliferative, antioxidant, anti-inflammatory, and anti-invasive features of melatonin, it performances as a beneficial agent to limit endometriosis; this involves several pathways including antiestrogenic, antioxidant, anti-inflammatory, and anti-apoptosis effects, as well as reducing the growth of E2-induced endometriotic tissue. Moreover, melatonin can favor sleep quality and decrease the unwanted signs in the patients. However, most of the data on melatonin accured from experimental works and additional clinical trials are needed. This review summarizes what is currently known regarding the influence of melatonin on endometriosis. AVAILABILITY OF DATA AND MATERIAL: Not applicable.

Non-invasive diagnosis of endometriosis: Immunologic and genetic markers

Endometriosis, a benign gynecologic and chronic inflammatory disease, is defined by the presence of endometrial tissue outside the uterus characterized mainly by pelvic pain and infertility. Because endometriosis affects approximately 10% of females, it represents a significant socioeconomic burden worldwide having tremendous impact on daily quality of life. Accurate and prompt diagnosis is crucial for the management of this debilitating disorder. Unfortunately, diagnosis is typically delayed to lack of specific symptoms and readily accessible biomarkers. Although histopathologic examination remains the current gold standard, this approach is highly invasive and not applicable for early screening. Recent work has focused on the identification of reliable biomarkers including immunologic, ie, immune cells, antibodies and cytokines, as well as genetic and biochemical markers, ie, microRNAs, lncRNAs, circulating and mitochondrial nucleic acids, along with some hormones, glycoproteins and signaling molecules. Confirmatory research studies are, however, needed to more fully establish these markers in the diagnosis, progression and staging of these endometrial lesions.

The latest advances in the pharmacological management of endometriosis

INTRODUCTION

Endometriosis is a benign disease, characterized by a wide range of symptoms and different degrees of severity, which is why therapy should be individually adapted to the patient's needs. Over the years, a lot of research has gone into finding new therapeutic approaches for this enigmatic disease.

AREAS COVERED

This review presents the latest advances in pharmacological management of endometriosis and is solely focused on studies published from 2010 to 2021.

EXPERT OPINION

Clinicians and researchers are constantly searching for new therapeutic strategies for endometriosis patients. As there are well-established treatments, however, any new medication should fulfill at least one of the three criteria: increased efficacy, comparable efficacy but a better safety profile, or treatments that have a lack of accompanying contraceptive effects that are seen in most endometriosis treatments. While some new substances show promising results, further studies are needed to demonstrate the fulfillment of one of the above-mentioned criteria.

Advances in targeting estrogen synthesis and receptors in patients with endometriosis

INTRODUCTION

Endometriosis is an estrogen-dependent disease on the background of progesterone resistance. Increased estrogen production, low estrogen metabolization, and altered estrogen receptors (ERs) expression contribute to the hyperestrogenic milieu within endometriotic lesions. Since estrogens play a crucial role in the pathogenesis of the disease, inhibition of estrogen production is one of the main targets of available and emerging drugs.

AREAS COVERED

Firstly, we described the molecular alterations responsible for estrogen dependence. Secondly, we reviewed available and emerging treatments that interfere, through central (gonadotropin-releasing hormone analogs (GnRH-a), GnRH antagonists) or local mechanisms (aromatase inhibitors (AIs), inhibitors of steroid sulfatase (STS) and hydroxysteroid dehydrogenase type 1 (17β-HSD1)), with estrogen dependence. Finally, we focused on emerging treatments targeting ERs (selective estrogen receptor modulators (SERMs), estrogen receptors agonists, and antagonists).

EXPERT OPINION

Available treatments interfering with estrogen pathways exert a contraceptive effect, have hypoestrogenic side effects, and cannot prevent or definitively treat the disease. Preclinical and animal studies are focusing on emerging drugs targeting ERs in order to overcome limitations of available treatments. These treatments may represent a promising option, as they may produce a more specific inhibition of disease activity within endometriotic implants, avoiding prolonged hypoestrogenic status and limiting systemic side effects.

Hormonal treatments for endometriosis: The endocrine background

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

Endocrine disruptor hexachlorobenzene induces cell migration and invasion, and enhances aromatase expression levels in human endometrial stromal cells

Endometriosis is the presence and growth of endometrial tissue outside of the uterus. Previous studies have suggested that endocrine disrupting chemicals such as organochlorine pesticides could be a risk factor for endometriosis. Hexachlorobenzene (HCB) is a weak ligand of the aryl hydrocarbon receptor (AhR) and promotes metalloproteinase and cyclooxygenase-2 (COX-2) expression, as well as, c-Src activation in human endometrial stromal cells (T-HESC) and in rat endometriosis model. Our aim was to evaluate the effect of HCB exposure on oestrogen receptor (ER) ɑ and β, progesterone receptor (PR) and aromatase expression, as well as, on cell migration and invasion in T-HESC and primary cultures of endometrial stromal cells from eutopic endometria of control subjects (ESC). Results show that HCB increases ERɑ and aromatase protein levels and reduces PR content in both T-HESC and ESC. However, the pesticide only increases ERβ expression in ESC, without changes in T-HESC. Moreover, cell migration and invasion are promoted by pesticide exposure involving the AhR, c-Src, COX-2 and ER pathways in T-HESC. HCB also triggers ERɑ activation via phosphorylation in Y537 through AhR/c-Src pathway. Our results provide experimental evidence that HCB induces alterations associated with endometriosis, suggesting that these mechanisms could contribute to pesticide exposure-induced endometriosis development.

Role of sex hormones in modulating breast and ovarian cancer associated pain

According to the National Cancer Institute in 2020 there will be an estimated 21,750 new ovarian cancer cases and 276,480 new breast cancer cases. Both breast and ovarian cancer are hormone dependent cancers, meaning they cannot grow without the presence of hormones. The two most studied hormones in these two cancers are estrogen and progesterone, which are also involved in the modulation of pain. The incidence of pain in breast and ovarian cancer is very high. Research about mechanisms involved in modulation of pain by hormones are still being debated, as some studies find estrogen to be anti-nociceptive and others pro-nociceptive in pain studies. Moreover, analgesic treatments for breast and ovarian cancer-associated pain are limited and often ineffective. In this review, we will focus on estrogen and progesterone mechanisms of action in modulation of pain and cancer. We will also discuss new treatment options for these types of cancer and associated-pain.

Pharmaceuticals targeting signaling pathways of endometriosis as potential new medical treatment: A review

Endometriosis (EM) is defined as endometrial tissues found outside the uterus. Growth and development of endometriotic cells in ectopic sites can be promoted via multiple pathways, including MAPK/MEK/ERK, PI3K/Akt/mTOR, NF-κB, Rho/ROCK, reactive oxidative stress, tumor necrosis factor, transforming growth factor-β, Wnt/β-catenin, vascular endothelial growth factor, estrogen, and cytokines. The underlying pathophysiological mechanisms include proliferation, apoptosis, autophagy, migration, invasion, fibrosis, angiogenesis, oxidative stress, inflammation, and immune escape. Current medical treatments for EM are mainly hormonal and symptomatic, and thus the development of new, effective, and safe pharmaceuticals targeting specific molecular and signaling pathways is needed. Here, we systematically reviewed the literature focused on pharmaceuticals that specifically target the molecular and signaling pathways involved in the pathophysiology of EM. Potential drug targets, their upstream and downstream molecules with key aberrant signaling, and the regulatory mechanisms promoting the growth and development of endometriotic cells and tissues were discussed. Hormonal pharmaceuticals, including melatonin, exerts proapoptotic via regulating matrix metallopeptidase activity while nonhormonal pharmaceutical sorafenib exerts antiproliferative effect via MAPK/ERK pathway and antiangiogenesis activity via VEGF/VEGFR pathway. N-acetyl cysteine, curcumin, and ginsenoside exert antioxidant and anti-inflammatory effects via radical scavenging activity. Natural products have high efficacy with minimal side effects; for example, resveratrol and epigallocatechin gallate have multiple targets and provide synergistic efficacy to resolve the complexity of the pathophysiology of EM, showing promising efficacy in treating EM. Although new medical treatments are currently being developed, more detailed pharmacological studies and large sample size clinical trials are needed to confirm the efficacy and safety of these treatments in the near future.

Altered immune environment in peritoneal endometriotic lesions: relationship to lesion appearance

OBJECTIVE

To study the localization of and quantify different immune cell populations in red, black, and white peritoneal endometriotic lesions and compare immune cell densities between lesions and the surrounding tissue.

DESIGN

Cross-sectional study.

SETTING

Teaching hospital, university research laboratory.

PATIENT(S)

Participants undergoing laparoscopic excision of endometriosis were recruited from gynecological operating theaters at Royal Prince Alfred Hospital, Sydney (n = 28).

INTERVENTION(S)

Immunohistochemical staining for and quantification of dendritic cells (mature and immature), T cells (effector, cytotoxic, and regulatory), B cells, and macrophages in endometriotic peritoneal lesions and the surrounding tissue.

MAIN OUTCOME MEASURE(S)

Immune cell densities and aggregates were quantified.

RESULT(S)

Red and black lesions are significantly more likely to be surrounded by immune cell aggregates than white lesions (P=.036). In the tissue surrounding the peritoneal endometriotic lesions, there was a consistent pattern of greater and more variable density of immune cell populations for red lesions than black or white lesions and a range of significant positive correlations between densities of different immune populations (all P≤.004; not observed within the lesion stroma).

CONCLUSION(S)

There is a greater presence of immune cells in the tissue surrounding earlier/red and black lesions than older scarred white lesions, particularly in the form of immune cell aggregates, indicating an immunologic response in close proximity to the adjacent lesion. The relationship between densities of immune populations in the tissue surrounding the lesions suggests complementary recruitment and local interactions between cells. Categorizing immune cell populations in proximity to peritoneal endometriotic lesions may improve the understanding of lesion persistence and transition to older white appearances. Early (red) peritoneal endometriotic lesions are surrounded by a greater density of immune cells, including immune aggregates, than later (black or white) lesions. These immune cells may support lesion persistence.

The expression and significance of leukemia inhibitory factor, interleukin-6 and vascular endothelial growth factor in Chinese patients with endometriosis

OBJECTIVE

To observe the levels of leukemia inhibitory factor (LIF), interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) in blood, peritoneal fluid, ectopic endometrial tissue, and ectopic endometrial stromal cells of patients with endometriosis, and to compare expression of IL-6, LIF and VEGF expression between endometriotic and non-endometriotic patients underwent laparoscopic surgery.

METHODS

Thirty-one patients who underwent laparoscopic surgery for endometriosis in our hospital from January 2018 to January 2020 were included in the observation group, and 32 patients who underwent laparoscopic surgery for uterine fibroids, ovarian serous cystadenoma, and ovarian teratomas, were included in the control group. The levels of LIF, IL-6 and VEGF in the blood and peritoneal fluid of the two groups of patients were detected. The levels of LIF, IL-6 and VEGF in ectopic endometrial tissue and self-paired eutopic endometrial tissue, ectopic endometrial stromal cells and self-paired eutopic endometrial stromal cells of patients in the observation group were detected. After treating the primary cultured ectopic endometrial stromal cells with LIF and IL-6 alone or in combination, the changes of VEGF mRNA of ectopic endometrial stromal cells and the VEGF levels in the supernatant were observed.

RESULTS

The levels of LIF, IL-6 and VEGF in the blood and peritoneal fluid of the observation group were all higher than those of the control group (P < 0.05), and the levels of LIF, IL-6 and VEGF in the peritoneal fluid of the observation group were significantly higher than those in the blood (P < 0.05). In the observation group, the expression levels of LIF-mRNA and IL-6 mRNA in the ectopic endometrial tissue were higher than those in the self-paired eutopic endometrial tissues (P < 0.05), while the expression level of VEGF mRNA in the ectopic endometrial tissues was lower than that in the self-paired eutopic endometrial tissues (P < 0.05). Besides, the mRNA expression levels of LIF, IL-6 and VEGF in ectopic endometrial stromal cells of the observation group were all higher than those in the self-paired eutopic endometrial stromal cells (P < 0.05). After stimulating ectopic endometrial stromal cells with LIF, IL-6 and LIF + IL-6, respectively, the VEGF levels in the supernatant were all significantly higher than that in the blank control group (P < 0.05).

CONCLUSION

The LIF, IL-6 and VEGF levels in blood and peritoneal fluid were increased in patients with endometriosis, and increased LIF and IL-6 in ectopic endometriosis stromal cells can play a synergistic role in increasing the VEGF levels, which may be involved in the occurrence and development of endometriosis.

Aromatase inhibitors for the treatment of endometriosis: a systematic review about efficacy, safety and early clinical development

INTRODUCTION

Pharmacotherapy has a key role in endometriosis treatment and management, however, a significant proportion of patients have only intermittent or limited benefits with current treatment options. Therefore, novel therapeutic approaches are necessary.

AREAS COVERED

This systematic review provides an overview of the efficacy and safety of aromatase inhibitors (AIs) as monotherapies and combination therapies for endometriosis. A systematic literature search was performed from January 1990 to April 2020 in the electronic database MEDLINE, EMBASE, The Cochrane Library, and Web of Science.

EXPERT OPINION

Based on the critical role of estrogens and the rate-limiting step in the production of the estrogens represented by the aromatase enzyme, AIs are a potential therapeutic option for women affected by endometriosis. Nevertheless, further research is needed to clarify the efficacy of AIs in this setting. Adverse effects need to be investigated to clarify the preventive role of add-back therapy. On that basis, AIs should be adopted only as second-line therapy in patients who are refractory to standard treatments in the setting of scientific research. Further studies should define best dosages, appropriate add-back therapies, administration routes, treatment length, and which patients may benefit more from AIs.

An assessment of the multifactorial profile of steroid-metabolizing enzymes and steroid receptors in the eutopic endometrium during moderate to severe ovarian endometriosis

BACKGROUND

Previous studies of expression profiles of major endometrial effectors of steroid physiology in endometriosis have yielded markedly conflicting conclusions, presumably because the relative effects of type of endometriosis, fertility history and menstrual cycle phases on the measured variables were not considered. In the present study, endometrial mRNA and protein levels of several effectors of steroid biosynthesis and action in patients with stage III-IV ovarian endometriosis (OE) with known fertility and menstrual cycle histories were compared with the levels in control endometrium to test this concept.

METHODS

Endometrial samples were collected from patients without endometriosis (n = 32) or OE stages III-IV (n = 52) with known fertility and cycle histories. qRT-PCR and immunoblotting experiments were performed to measure levels of NR5A1, STAR, CYP19A1, HSD17Bs, ESRs and PGR transcripts and proteins, respectively. Tissue concentrations of steroids (P4, T, E1 and E2) were measured using ELISAs.

RESULTS

The levels of expression of aromatase and ERβ were lower (P < 0.0001) and 17β-HSD1 (P < 0.0001) and PRA (P < 0.01) were higher in OE endometrium. Lower aromatase levels and higher 17β-HSD1 levels were detected in fertile (aromatase: P < 0.05; 17β-HSD1: P < 0.0001) and infertile (aromatase: P < 0.0001; 17β-HSD1: P < 0.0001) OE endometrium than in the matched control tissues. Both proliferative (PP) and secretory (SP) phase OE samples expressed aromatase (P < 0.0001) and ERβ (PP: P < 0.001; SP: P < 0.01) at lower levels and 17β-HSD1 (P < 0.0001) and PRA (PP: P < 0.01; SP: P < 0.0001) at higher levels than matched controls. Higher 17β-HSD1 (P < 0.01) and E2 (P < 0.05) levels and a lower (P < 0.01) PRB/PRA ratio was observed in infertile secretory phase OE endometrium than in control.

CONCLUSIONS

We report that dysregulated expression of 17β-HSD1 and PGR resulting in hyperestrogenism and progesterone resistance during the secretory phase of the menstrual cycle, rather than an anomaly in aromatase expression, was the hallmark of eutopic endometrium from infertile OE patients. Furthermore, the results provide proof of concept that the fertility and menstrual cycle histories exerted relatively different effects on steroid physiology in the endometrium from OE patients compared with the control subjects.

Evaluation of the effectiveness of letrozole in the treatment of experimentally modeled endometriosis in rats

The necessity of finding new drugs for the treatment of endometriosis is stipulated by significant number of recurrences, side effects, and high cost of treatment. Increased activity of aromatase in endometrioid heterotopies is revealed. That is why, aromatase inhibitors may be effective in the treatment of endometriosis. In this study, endometriosis was modeled in rats by autotransplantation of uterine fragments to peritoneum, which was supplemented by ovariectomy and ethinylestradiol replacement therapy. After 14 ± 2 days, laboratory animals underwent laparoscopy to measure formed heterotopies and then the rats were divided into two groups. Nine animals were receiving letrozole (0.5 mg/kg/day) therapy for 3 weeks. The rats of the control group did not receive treatment (n = 11). At the end of the experiment (21 ± 3 days after laparoscopy), re-evaluation and determination of size of heterotopies as well as histological study were carried out in two groups. In all the rats of the main group, treated with letrozole, the decrease in the size of heterotopies was revealed; the percentage of reduction was 79.92% ± 7.89% (p < 0.0001). Growth of all endometriotic foci was observed in the control group. Thus, the use of the aromatase inhibitor letrozole in the treatment of endometriosis is effective.

Calligonum comosum (Escanbil) extract exerts anti-angiogenic, anti-proliferative and anti-inflammatory effects on endometriotic lesions

ETHNOPHARMACOLOGICAL RELEVANCE

Calligonum comosum is a desert plant that is applied in traditional folkloric medicine for the treatment of abnormally heavy or prolonged menstruation and menstrual cramps. Moreover, it has been suggested for the treatment of infertility-causing conditions. Its bioactive chemical constituents inhibit multiple processes, such as angiogenesis, inflammation and invasive tissue growth, which may be beneficial in the therapy of endometriosis.

AIM OF THE STUDY

We investigated the effects of Calligonum comosum on the development of endometriotic lesions.

MATERIALS AND METHODS

We evaluated the anti-angiogenic activity of Calligonum comosum ethyl acetate fraction (CCEAF) in different in vitro angiogenesis assays. Moreover, we surgically induced endometriotic lesions in BALB/c mice, which received 50 mg/kg Calligonum comosum total extract (CCTE) or vehicle (control) over 4 weeks. The growth, cyst formation, vascularization and immune cell infiltration of the lesions were assessed with high-resolution ultrasound imaging, caliper measurements, histology and immunohistochemistry.

RESULTS

CCEAF doses of up to 10 μg/mL did not impair the viability of human dermal microvascular endothelial cells (HDMEC), but dose-dependently suppressed their migration, tube formation and sprouting, indicating a substantial anti-angiogenic effect of CCEAF. Furthermore, CCTE significantly inhibited the growth and cyst formation of developing murine endometriotic lesions when compared to vehicle-treated controls. This was associated with a reduced vascularization, cell proliferation and immune cell infiltration.

CONCLUSIONS

Our findings show that Calligonum comosum targets multiple, fundamental processes in the pathogenesis of endometriosis, which may be beneficial for the treatment of this common gynecological disorder.

Sphingosine 1 Phosphate (S1P) Increased IL-6 Expression and Cell Growth in Endometriotic Cells

OBJECTS

There is growing evidence that sphingosine 1-phosphate (S1P) is involved in inflammatory diseases. As endometriosis is known as an inflammatory disease, we investigated the role of S1P system in the development of endometriosis.

METHODS

The expression of sphingosine kinase (SphK) 1 in endometriosis lesions was examined by immunohistochemistry. The cystic fluid of ovarian cysts/tumors were obtained to measure S1P concentrations. Endometriotic stromal cells (ESC) derived from endometrioma were used for in vitro experiments.

RESULTS

Sphingosine kinase 1 was detected in epithelium and stromal cells of endometriotic lesions. The mean S1P concentration in the cystic fluid of endometriomas was higher than that in nonendometriomas significantly (98.2 nM vs less than 1.5 nM, P < .01). Interleukin-1β (IL-1β) or transforming growth factor-β exhibited 2.7-fold and 11.5-fold increase in SphK1 messenger RNA (mRNA) expression in ESC, respectively (P < .01). Higher dose of S1P (125nM) increased the cell number of ESC by 20%, and low dose of S1P (1.25 nM and 12.5 nM) induced IL-6 mRNA production and IL-6 secretion by ESC dose-dependently. JTE013, an antagonist for S1PR2, partially suppressed IL-6 induction by S1P (P < .05). JTE013 and VPC23019, an antagonist for S1PR1 and S1PR3, suppressed the ESC proliferation induced by S1P.

CONCLUSION

The present study for the first time proved that the SphK-S1P-S1PR axis play a role of accelerating inflammation and growth of endometriotic cells.

Regulation of Inflammation Pathways and Inflammasome by Sex Steroid Hormones in Endometriosis

Endometriosis is a gynecological disorder characterized by the growth of endometrial tissue (glands and stroma) outside the uterus, mainly in the peritoneal cavity, ovaries, and intestines. This condition shows estrogen dependency and progesterone resistance, and it has been associated with chronic inflammation, severe pain, and infertility, which negatively affect the quality of life in reproductive women. The molecular mechanisms involved in the pathogenesis of endometriosis are not completely understood; however, inflammation plays a key role in the pathophysiology of the disease, mainly by altering the function of immune cells (macrophages, natural killer, and T cells) and increasing levels of pro-inflammatory mediators in the peritoneal cavity, endometrium, and blood. These immune alterations inhibit apoptotic pathways and promote adhesion and proliferation of endometriotic cells, as well as angiogenesis and neurogenesis in endometriotic lesions. It has been demonstrated that hormonal alterations in endometriosis are related to the inflammatory unbalance in this disease. Particularly, steroid hormones (mainly estradiol) promote the expression and release of pro-inflammatory factors. Excessive inflammation in endometriosis contributes to changes of hormonal regulation by modulating sex steroid receptors expression and increasing aromatase activity. In addition, dysregulation of the inflammasome pathway, mediated by an alteration of cellular responses to steroid hormones, participates in disease progression through preventing cell death, promoting adhesion, invasion, and cell proliferation. Furthermore, inflammation is involved in endometriosis-associated infertility, which alters endometrium receptivity by impairing biochemical responses and decidualization. The purpose of this review is to present current research about the role of inflammasome in the pathogenesis of endometriosis as well as the molecular role of sex hormones in the inflammatory responses in endometriosis.

Exposure to environmental concentrations of hexachlorobenzene induces alterations associated with endometriosis progression in a rat model

Hexachlorobenzene (HCB) is a dioxin-like compound widely distributed and is a weak ligand of the aryl hydrocarbon receptor (AhR). Endometriosis is a disease characterized by growth of endometrial tissue in ectopic sites. Our aim was to investigate the impact of HCB on the endocrine, invasion and inflammatory parameters in a rat endometriosis model surgically induced. Female rats were exposed to HCB (1, 10 and 100 mg/kg b.w.) during 30 days. Results showed that HCB increases endometriotic like-lesions (L) volume in a dose-dependent manner. In L, HCB10 increases microvessel density (immunohistochemistry) and the vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2) and AhR levels (Western Blot), while HCB1 enhances aromatase expression (Western Blot). In addition, in eutopic endometrium (EU), HCB10/HCB100 augments microvessel density, VEGF and MMP-9 expression, while HCB1/HCB10 increases tumor necrosis factor-α (TNF-α) content in peritoneal fluid (ELISA). Interestingly, both L and EU from HCB-treated rats exhibited higher estrogen receptor α (ERα) (immunohistochemistry) and metalloproteases (MMP)-2 and -9 levels (Western Blot), as well as lower progesterone receptor (PR) expression (immunohistochemistry) than in control rats. Environmentally relevant concentrations of HCB could contribute to abnormal changes associated with endometriosis progression and development.

Intracrine Regulation of Estrogen and Other Sex Steroid Levels in Endometrium and Non-gynecological Tissues; Pathology, Physiology, and Drug Discovery

Our understanding of the intracrine (or local) regulation of estrogen and other steroid synthesis and degradation expanded in the last decades, also thanks to recent technological advances in chromatography mass-spectrometry. Estrogen responsive tissues and organs are not passive receivers of the pool of steroids present in the blood but they can actively modify the intra-tissue steroid concentrations. This allows fine-tuning the exposure of responsive tissues and organs to estrogens and other steroids in order to best respond to the physiological needs of each specific organ. Deviations in such intracrine control can lead to unbalanced steroid hormone exposure and disturbances. Through a systematic bibliographic search on the expression of the intracrine enzymes in various tissues, this review gives an up-to-date view of the intracrine estrogen metabolisms, and to a lesser extent that of progestogens and androgens, in the lower female genital tract, including the physiological control of endometrial functions, receptivity, menopausal status and related pathological conditions. An overview of the intracrine regulation in extra gynecological tissues such as the lungs, gastrointestinal tract, brain, colon and bone is given. Current therapeutic approaches aimed at interfering with these metabolisms and future perspectives are discussed.

Progesterone Resistance in Endometriosis: an Acquired Property?

Endometriosis is the growth of endometrial tissue outside the uterus and is characterized by progesterone resistance and changes in global and progesterone target gene expression. However, the mechanism behind this and whether it is innate, acquired, or present in both the eutopic and ectopic tissue in not always clear. We find large-scale gene expression studies in eutopic tissue, indicative of progesterone resistance, are often contradictory, potentially due to the dynamic nature of this tissue, whereas suppressed progesterone receptor expression is supported in ectopic but not eutopic tissue. This suggests more studies are required in eutopic tissue particularly, and that potentially the suppressed progesterone receptor (PR) expression is a consequence of the pathogenic process and exposure to the peritoneal environment.

Expression of inflammatory cytokines in serum and peritoneal fluid from patients with different stages of endometriosis

OBJECTIVE

To investigate the level of inflammatory cytokines in endometriosis patients, and explore the relationship between IL-37 concentration and endometriosis stages.

METHODS

Inflammatory cytokine concentrations from 27 patients with different stages of endometriosis and 52 controls without endometriosis were examined by ELISA. Then, the specificity and sensitivity of cytokines for distinguishing from controls and the different stages of endometriosis were analyzed using the ROC curve.

RESULTS

The difference in serum concentrations of IL-37, IL-17A, IL-10, and IL-2 between the endometriosis and control groups was statistically significant (p < .01). Compared with controls, significantly higher levels of serum IL-37 and IL-10, and significantly lower levels of serum IL-17A and IL-2 were detected in patients with endometriosis (p < .01). Furthermore, IL-2 concentration was significantly higher in peritoneal fluid (PF) in the endometriosis group (p = .0034), IL-10 concentrations in PF were significantly lower in the early-stages of endometriosis than in the more advanced groups (p = .0439), and IL-4 concentration in PF was significantly higher in more advanced endometriosis (p = .0228). The sensitivity and specificity of serum IL-37 for distinguishing endometriosis were 81.48% and 83.33%, respectively, and the cutoff concentration was 69.84 pg/ml. For IL-17A, the sensitivity and specificity were 96.30% and 100%, respectively, and the cutoff concentration was 57.54 pg/ml. For IL-10, the sensitivity and specificity was 92.59% and 100%, respectively, and the cutoff concentration was 3.301 pg/ml. For IL-2, the sensitivity and specificity were 74.07% and 93.75%, respectively, and the cutoff concentration was 1.813 pg/ml. For PF IL-2, the sensitivity and specificity were 29.73% and 100%, respectively, and the cutoff concentration was 1.06 pg/ml.

CONCLUSIONS

IL-37, IL-17A, IL-10, and IL-2 may play a significant role in immune response in endometriosis. IL-37 levels may be used as a diagnostic marker for endometriosis.

Absence of Effect of Intravaginal Miconazole, Clindamycin, Nonoxynol-9, and Tampons on the Pharmacokinetics of an Anastrozole/Levonorgestrel Intravaginal Ring

A study was performed to investigate the effect of an intravaginally administered antimycotic, an antibiotic, and a spermicide plus the co-usage of tampons on the pharmacokinetics (PK) of levonorgestrel (LNG) and anastrozole (ATZ) administered as an intravaginal ring (IVR) releasing 1050 μg ATZ per day and 40 μg LNG per day. In this parallel-group, randomized, open-label study, healthy premenopausal women received an IVR as the main treatment. Comedications were administered on 3 consecutive evenings during treatment with IVR on days 9-11 (group A, 400 mg miconazole; group B, 100 mg clindamycin; group C, 75 mg nonoxynol-9); tampon co-usage (group D) was performed on days 20-23. The primary PK parameter was the average plasma concentration (C_av,ss ) of ATZ and LNG at defined intervals, mainly prior to, during, and up to 7 days after the start of comedication. Fifty-two subjects were included, and at least 11 subjects per group completed the treatments. Overall, the medications and comedications were safe and well tolerated. Very similar ATZ and LNG plasma levels were observed across all groups. The calculated ratios of C_av,ss confirmed the absence of PK interactions because all relevant point estimates and 90% confidence intervals were within the range of 0.800-1.250, which is typically used in bioequivalence studies. These results demonstrate the absence of PK interactions between ATZ/LNG released from IVR and the tested antibiotic, antimycotic, spermicide, and tampons. Therefore, no restrictions for the use of the IVR are needed to continue the clinical program intended to treat endometriosis symptoms.

Prospects of metformin in the treatment of endometriosis

According to recent year studies, the classical biguanide metformin has antiproliferative, proapoptotic and anti-inflammatory effects in addition to the main hypoglycemic effect. There are clinical and experimental studies these effects in the therapy of oncological and benign hyperplastic diseases. There is no data about the clinical efficacy of metformin in the therapy of endometriosis in the domestic literature, and there were a few studies in foreign sources. There was a decrease in the severity of the pain syndrome and an increase of pregnancy rate in two clinical studies with small samples. However, future studies are needed to investigate the mechanisms of the target drug effect and to develop effective regimens for the treatment of endometriosis.

Biomarkers in endometriosis: challenges and opportunities

Endometriosis is a debilitating gynecologic disease affecting millions of women across the world, with symptoms including dysmenorrhea, chronic pelvic pain, and infertility. Theorized to stem from the phenomenon of retrograde menstruation, the diagnosis of endometriosis is typically delayed by 8-10 years owing to misinterpretation of symptoms as common menstrual cramps in adolescent girls and young women. With increased incidence of endometriosis in young girls correlated with earlier menarche, the development of diagnostic biomarkers is imperative for diagnosing and treating women afflicted with endometriosis as early as we can. In the past few years, multiple reviews highlighted the list of potential diagnostic candidates in peritoneal fluid, blood, urine, and endometrial biopsies from endometriosis patients in different stages of disease and menstrual cycle. In this review, we explore the opportunities and challenges facing the field of diagnostic biomarkers for endometriosis. We highlight the importance of eutopic endometrium as a source of potential diagnostic biomarkers by looking at the expression levels of noncoding RNA in tissue as well as in blood. Finally, we discuss some of the challenges that hinder our efforts in validating candidate diagnostic biomarkers for endometriosis.

Model-Based Dose Selection for Intravaginal Ring Formulations Releasing Anastrozole and Levonorgestrel Intended for the Treatment of Endometriosis Symptoms

Pharmacokinetics (PK) of anastrozole (ATZ) and levonorgestrel (LNG) released from an intravaginal ring (IVR) intended to treat endometriosis symptoms were characterized, and the exposure-response relationship focusing on the development of large ovarian follicle-like structures was investigated by modeling and simulation to support dose selection for further studies. A population PK analysis and simulations were performed for ATZ and LNG based on clinical phase 1 study data from 66 healthy women. A PK/PD model was developed to predict the probability of a maximum follicle size ≥30 mm and the potential contribution of ATZ beside the known LNG effects. Population PK models for ATZ and LNG were established where the interaction of LNG with sex hormone-binding globulin (SHBG) as well as a stimulating effect of estradiol on SHBG were considered. Furthermore, simulations showed that doses of 40 μg/d LNG combined with 300, 600, or 1050 μg/d ATZ reached anticipated exposure levels for both drugs, facilitating selection of ATZ and LNG doses in the phase 2 dose-finding study. The main driver for the effect on maximum follicle size appears to be unbound LNG exposure. A 50% probability of maximum follicle size ≥30 mm was estimated for 40 μg/d LNG based on the exposure-response analysis. ATZ in the dose range investigated does not increase the risk for ovarian cysts as occurs with LNG at a dose that does not inhibit ovulation.

Selective Estrogen-Receptor Modulators and Aromatase Inhibitors: Promising New Medical Therapies for Endometriosis?

Endometriosis is an estrogen-dependent disease and estrogen-related pathways are imbalanced in women with endometriosis. One of the key enzymes in estrogen synthesis is aromatase. Inhibiting this pathway at several points is a promising idea for the treatment of endometriosis. The third generation of aromatase inhibitors is becoming more potent in efficacy, with fewer side effects than previous generations, but cotreatment with other hormones is needed to inhibit ovarian stimulation. Other components that promote estrogen synthesis such as COX-2 can also be potentially targeted. Selective estrogen-receptor modulators could also be interesting in view of their tissue-specific effect. However, all these new drugs are still in an early phase of development. At present, it is too early to conclude that aromatase inhibitors, COX-2 inhibitors or selective estrogen-receptor modulators really present any added value compared with the existing drugs that can be used to achieve hormonal suppression in the medical treatment of endometriosis.

Effects of cisplatin and letrozole on surgically induced endometriosis and comparison of the two medications in a rat model

This study was to investigate the effects of cisplatin (CDDP) and letrozole on surgically induced endometriosis and comparison of the two drugs in a rat model. Endometriosis was surgically induced by autologous transplantation of endometrial pieces. Thirty model rats were divided into three groups, randomly. Group 1 (n=10) served as control and received no medication. Group 2 (n=10) received 0.2mg/kg/day of oral letrozole. Group 3 (n=10) received 35mg/m(2) CDDP via peritoneal perfusion every four days. All the rats were treated for 24days. The growth and histologic score of the implants were evaluated. The proliferation- and angiogenesis-associated proteins were assessed using immunohistochemistry and western blotting. The serum sex hormones were assayed using ELISA. After the medication, the growth and histologic score of the implants were significantly lower in the 2 and 3 groups than in the control group. The protein expressions of vascular endothelial growth factor (VEGF), aromatase P450 (P450arom), transforming growth factor-beta (TGF-β), and matrix metalloproteinase (MMP)-2, were significantly lower in groups 2 and 3 than in the control group. Further, the P450arom level was lower in the letrozole group than in the CDDP group. The TGF-β and MMP-2 levels were lower in the CDDP group than in the letrozole group. Serum T level was significantly higher in the letrozole group, and serum E2 level was lower in the letrozole group. In conclusion, cisplatin and letrozole caused similar regression of the implants in the endometriosis model rats. But their effects on the proliferation- and angiogenesis-associated protein expressions and the serum sex hormone levels were different. Cisplatin and letrozole might cause the effects in the endometriotic foci through different mechanism.

Endometrial biomarkers for the non-invasive diagnosis of endometriosis

BACKGROUND

About 10% of reproductive-aged women suffer from endometriosis, which is a costly, chronic disease that causes pelvic pain and subfertility. Laparoscopy is the gold standard diagnostic test for endometriosis, but it is expensive and carries surgical risks. Currently, there are no non-invasive tests available in clinical practice that accurately diagnose endometriosis. This is the first diagnostic test accuracy review of endometrial biomarkers for endometriosis that utilises Cochrane methodologies, providing an update on the rapidly expanding literature in this field.

OBJECTIVES

To determine the diagnostic accuracy of the endometrial biomarkers for pelvic endometriosis, using a surgical diagnosis as the reference standard. We evaluated the tests as replacement tests for diagnostic surgery and as triage tests to inform decisions to undertake surgery for endometriosis.

SEARCH METHODS

We did not restrict the searches to particular study designs, language or publication dates. To identify trials, we searched the following databases: CENTRAL (2015, July), MEDLINE (inception to May 2015), EMBASE (inception to May 2015), CINAHL (inception to April 2015), PsycINFO (inception to April 2015), Web of Science (inception to April 2015), LILACS (inception to April 2015), OAIster (inception to April 2015), TRIP (inception to April 2015) and ClinicalTrials.gov (inception to April 2015). We searched DARE and PubMed databases up to April 2015 to identify reviews and guidelines as sources of references to potentially relevant studies. We also performed searches for papers recently published and not yet indexed in the major databases. The search strategies incorporated words in the title, abstract, text words across the record and the medical subject headings (MeSH).

SELECTION CRITERIA

We considered published peer-reviewed, randomised controlled or cross-sectional studies of any size that included prospectively collected samples from any population of reproductive-aged women suspected of having one or more of the following target conditions: ovarian, peritoneal or deep infiltrating endometriosis (DIE).

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from each study and performed a quality assessment. For each endometrial diagnostic test, we classified the data as positive or negative for the surgical detection of endometriosis and calculated the estimates of sensitivity and specificity. We considered two or more tests evaluated in the same cohort as separate data sets. We used the bivariate model to obtain pooled estimates of sensitivity and specificity whenever sufficient data were available. The predetermined criteria for a clinically useful test to replace diagnostic surgery was one with a sensitivity of 94% and a specificity of 79%. The criteria for triage tests were set at sensitivity at or above 95% and specificity at or above 50%, which in case of negative results rules out the diagnosis (SnOUT test) or sensitivity at or above 50% with specificity at or above 95%, which in case of positive result rules in the diagnosis (SpIN test).

MAIN RESULTS

We included 54 studies involving 2729 participants, most of which were of poor methodological quality. The studies evaluated endometrial biomarkers either in specific phases of the menstrual cycle or outside of it, and the studies tested the biomarkers either in menstrual fluid, in whole endometrial tissue or in separate endometrial components. Twenty-seven studies evaluated the diagnostic performance of 22 endometrial biomarkers for endometriosis. These were angiogenesis and growth factors (PROK-1), cell-adhesion molecules (integrins α3β1, α4β1, β1 and α6), DNA-repair molecules (hTERT), endometrial and mitochondrial proteome, hormonal markers (CYP19, 17βHSD2, ER-α, ER-β), inflammatory markers (IL-1R2), myogenic markers (caldesmon, CALD-1), neural markers (PGP 9.5, VIP, CGRP, SP, NPY, NF) and tumour markers (CA-125). Most of these biomarkers were assessed in single studies, whilst only data for PGP 9.5 and CYP19 were available for meta-analysis. These two biomarkers demonstrated significant diversity for the diagnostic estimates between the studies; however, the data were too limited to reliably determine the sources of heterogeneity. The mean sensitivities and specificities of PGP 9.5 (7 studies, 361 women) were 0.96 (95% confidence interval (CI) 0.91 to 1.00) and 0.86 (95% CI 0.70 to 1.00), after excluding one outlier study, and for CYP19 (8 studies, 444 women), they were were 0.77 (95% CI 0.70 to 0.85) and 0.74 (95% CI 0.65 to 84), respectively. We could not statistically evaluate other biomarkers in a meaningful way. An additional 31 studies evaluated 77 biomarkers that showed no evidence of differences in expression levels between the groups of women with and without endometriosis.

AUTHORS' CONCLUSIONS

We could not statistically evaluate most of the biomarkers assessed in this review in a meaningful way. In view of the low quality of most of the included studies, the findings of this review should be interpreted with caution. Although PGP 9.5 met the criteria for a replacement test, it demonstrated considerable inter study heterogeneity in diagnostic estimates, the source of which could not be determined. Several endometrial biomarkers, such as endometrial proteome, 17βHSD2, IL-1R2, caldesmon and other neural markers (VIP, CGRP, SP, NPY and combination of VIP, PGP 9.5 and SP) showed promising evidence of diagnostic accuracy, but there was insufficient or poor quality evidence for any clinical recommendations. Laparoscopy remains the gold standard for the diagnosis of endometriosis, and using any non-invasive tests should only be undertaken in a research setting. We have also identified a number of biomarkers that demonstrated no diagnostic value for endometriosis. We recommend that researchers direct future studies towards biomarkers with high diagnostic potential in good quality diagnostic studies.

Potential role of estrogen in maintaining the imbalanced sympathetic and sensory innervation in endometriosis

Endometriosis, one of the most common benign gynecological diseases, affects millions of women of childbearing age. Endometriosis-associated pain is a major cause of disability and compromised quality of life in women. Neuropathic mechanisms are believed to play an important role. An imbalanced sympathetic and sensory innervation (reduced sympathetic innervation, with unchanged or increased sensory innervation in endometriotic lesions) has been demonstrated in endometriosis in recent studies. And it is believed to contribute to the pathogenesis of endometriosis-associated pain. It is primarily considered to be a natural adaptive program to endometriosis-associated inflammation. However, it is important to further clarify whether other potential modulating factors are involved in this dysregulation. It is generally accepted that endometriosis is an estrogen dependent disease. Higher estrogen biosynthesis and lower estrogen inactivation in endometriosis can lead to an excess of local estrogen in endometriotic lesions. In addition to its proliferative and anti-inflammatory actions, local estrogen in endometriosis also exerts potential neuromodulatory effects on the innervation in endometriosis. The aim of this review is to highlight the role of estrogen in mediating this imbalanced sympathetic and sensory innervation in endometriosis, through direct and indirect mechanisms on sympathetic and sensory nerves. Theoretical elaboration of the underlying mechanisms provides new insights in supporting the therapeutic role of estrogen in endometriosis-associated pain.

GnRH and GnRH receptors in the pathophysiology of the human female reproductive system

BACKGROUND

Human reproduction depends on an intact hypothalamic-pituitary-gonadal (HPG) axis. Hypothalamic gonadotrophin-releasing hormone (GnRH) has been recognized, since its identification in 1971, as the central regulator of the production and release of the pituitary gonadotrophins that, in turn, regulate the gonadal functions and the production of sex steroids. The characteristic peculiar development, distribution and episodic activity of GnRH-producing neurons have solicited an interdisciplinary interest on the etiopathogenesis of several reproductive diseases. The more recent identification of a GnRH/GnRH receptor (GnRHR) system in both the human endometrium and ovary has widened the spectrum of action of the peptide and of its analogues beyond its hypothalamic function.

METHODS

An analysis of research and review articles published in international journals until June 2015 has been carried out to comprehensively summarize both the well established and the most recent knowledge on the physiopathology of the GnRH system in the central and peripheral control of female reproductive functions and diseases.

RESULTS

This review focuses on the role of GnRH neurons in the control of the reproductive axis. New knowledge is accumulating on the genetic programme that drives GnRH neuron development to ameliorate the diagnosis and treatment of GnRH deficiency and consequent delayed or absent puberty. Moreover, a better understanding of the mechanisms controlling the episodic release of GnRH during the onset of puberty and the ovulatory cycle has enabled the pharmacological use of GnRH itself or its synthetic analogues (agonists and antagonists) to either stimulate or to block the gonadotrophin secretion and modulate the functions of the reproductive axis in several reproductive diseases and in assisted reproduction technology. Several inputs from other neuronal populations, as well as metabolic, somatic and age-related signals, may greatly affect the functions of the GnRH pulse generator during the female lifespan; their modulation may offer new possible strategies for diagnostic and therapeutic interventions. A GnRH/GnRHR system is also expressed in female reproductive tissues (e.g. endometrium and ovary), both in normal and pathological conditions. The expression of this system in the human endometrium and ovary supports its physiological regulatory role in the processes of trophoblast invasion of the maternal endometrium and embryo implantation as well as of follicular development and corpus luteum functions. The GnRH/GnRHR system that is expressed in diseased tissues of the female reproductive tract (both benign and malignant) is at present considered an effective molecular target for the development of novel therapeutic approaches for these pathologies. GnRH agonists are also considered as a promising therapeutic approach to counteract ovarian failure in young female patients undergoing chemotherapy.

CONCLUSIONS

Increasing knowledge about the regulation of GnRH pulsatile release, as well as the therapeutic use of its analogues, offers interesting new perspectives in the diagnosis, treatment and outcome of female reproductive disorders, including tumoral and iatrogenic diseases.

Differential expression of upstream stimulatory factor (USF) 2 variants in eutopic endometria from women with endometriosis: estradiol regulation

BACKGROUND

Endometriosis, pro-inflammatory and invasive benign disease estrogen dependent, abnormally express in endometria the enzyme P450Arom, positively regulated by steroid factor-1 (SF-1). Our objective was to study the nuclear protein contents of upstream stimulating factor 2 (USF2a and USF2b), a positive regulator of SF-1, throughout the menstrual cycle in eutopic endometria from women with and without (control) endometriosis and the involvement of nuclear estrogen receptors (ER) and G-coupled protein estrogen receptor (GPER)-1.

RESULTS

Upstream stimulating factor 2 protein contents were higher in mid (USF2b) and late (USF2a and USF2b) secretory phase in eutopic endometria from endometriosis than control (p < 0.05). In isolated control epithelial cells incubated with E2 and PGE2, to resemble the endometriosis condition, the data showed: (a) significant increase of USF2a and USF2b nuclear protein contents when treated with E2, PPT (specific agonist for ERα) or G1 (specific agonist for GPER1); (b) no increase in USF2 binding to SF-1 E-Box/DNA consensus sequence in E2-treated cells; (c) USF2 variants protein contents were not modified by PGE2; (d) SF-1 nuclear protein content was significantly higher than basal when treated with PGE2, E2 or G1, stimulation unaffected by ICI (nuclear ER antagonist); and (e) increased (p < 0.05) cytosolic protein contents of P450Arom when treated with PGE2, E2, PPT or G1 compared to basal, effect that was additive with E2 + PGE2 together. Nevertheless, in endometriosis cells, the high USF2, SF-1 and P450Arom protein contents in basal condition were unmodified.

CONCLUSION

These data strongly suggest that USF2 variants and P450Arom are regulated by E2 through ERα and GPER1, whereas SF-1 through GPER1, visualized by the response of the cells obtained from control endometria, being unaffected the endogenously stimulated cells from endometriosis origin. The lack of E2 stimulation on USF2/SF-1 E-Box/DNA-sequence binding and the absence of PGE2 effect on USF2 variants opposite to the strong induction that they exert on SF1 and P450 proteins suggest different mechanisms and indirect regulations. The sustained USF2 variants protein expression during the secretory phase in eutopic endometria from women with endometriosis may participate in the pathophysiology of this disease strongly associated with infertility and its characteristic endometrial invasion to ectopic sites in the pelvic cavity.

Role of nociceptor estrogen receptor GPR30 in a rat model of endometriosis pain

Endometriosis, the most common cause of chronic pelvic pain, is an estrogen-dependent disease in which classic estrogen receptors (ERα, ERβ) play an important role. Although recent evidence suggests that the novel G protein-coupled estrogen receptor (GPR30) also plays a key role in the progression of endometriosis, whether it is also involved in endometriosis pain is still unknown. Here we tested the hypothesis that GPR30 expressed by nociceptors contributes to endometriosis pain. Intramuscular injection of the GPR30 agonists raloxifene or 17β-estradiol produced a fast-onset, persistent, mechanical hyperalgesia at the site of the injection. Intrathecal antisense (AS) oligodeoxynucleotides (ODN), but not mismatch (MM) ODN, targeting mRNA for GPR30 markedly inhibited its protein expression in nociceptors and attenuated the mechanical hyperalgesia induced by local raloxifene or 17β-estradiol. Pretreatment with the GPR30 antagonist G-36 also inhibited the hyperalgesia induced by raloxifene or 17β-estradiol in naive control rats. Surgical implant of autologous uterine tissue onto the gastrocnemius muscle, which induces endometriosis-like lesions, produced local mechanical hyperalgesia. Intrathecal AS, but not MM, ODN targeting GPR30 mRNA reversibly inhibited the mechanical hyperalgesia at the site of endometriotic lesions. Finally, intralesional injection of the GPR30 antagonist G-36 also inhibited the mechanical hyperalgesia at the site of ectopic uterine tissue. We conclude that local GPR30 agonists produce persistent mechanical hyperalgesia in naive female rats, whereas local GPR30 antagonists inhibit mechanical hyperalgesia in a model of endometriosis pain. Thus, GPR30 expressed by nociceptors innervating ectopic uterine lesions might play a major role in endometriosis pain.

Screening of a panel of steroid-related genes showed polymorphisms of aromatase genes confer susceptibility to advanced stage endometriosis in the Taiwanese Han population

OBJECTIVE

To establish a multilocus model for studying the effect of steroid-related genes on advanced stage endometriosis.

MATERIALS AND METHODS

A total of 121 patients with advanced stage endometriosis and 171 control women were included. Eighteen single-nucleotide polymorphisms (SNPs) from nine genes (HSD17B1, HSD17B2, HSD17B5, HSD17B6, CYP17, CYP19, ERα, ERβ, and PGR) were genotyped using the TaqMan assays. Logistic regression models were used to evaluate the genetic effects, with adjustment for other covariates.

RESULTS

Only the presence of the mutant CYP19 (aromatase gene) was associated with a significantly increased risk of endometriosis after adjusting for age, BMI, and parity (p = 0.002, OR = 2.69; 95% CI = 1.44-5.02). No association was ascertained between the other investigated SNPs and endometriosis.

CONCLUSION

Polymorphisms of the aromatase gene confer susceptibility to advanced stage endometriosis in the Taiwanese Han population.

Medical treatments for endometriosis-associated pelvic pain

The main sequelae of endometriosis are represented by infertility and chronic pelvic pain. Chronic pelvic pain causes disability and distress with a very high economic impact. In the last decades, an impressive amount of pharmacological agents have been tested for the treatment of endometriosis-associated pelvic pain. However, only a few of these have been introduced into clinical practice. Following the results of the controlled studies available, to date, the first-line treatment for endometriosis associated pain is still represented by oral contraceptives used continuously. Progestins represent an acceptable alternative. In women with rectovaginal lesions or colorectal endometriosis, norethisterone acetate at low dosage should be preferred. GnRH analogues may be used as second-line treatment, but significant side effects should be taken into account. Nonsteroidal anti-inflammatory drugs are widely used, but there is inconclusive evidence for their efficacy in relieving endometriosis-associated pelvic pain. Other agents such as GnRH antagonist, aromatase inhibitors, immunomodulators, selective progesterone receptor modulators, and histone deacetylase inhibitors seem to be very promising, but there is not enough evidence to support their introduction into routine clinical practice. Some other agents, such as peroxisome proliferator activated receptors-γ ligands, antiangiogenic agents, and melatonin have been proven to be efficacious in animal studies, but they have not yet been tested in clinical studies.

Surface plasmon resonance imaging biosensors for aromatase based on a potent inhibitor and a specific antibody: Sensor development and application for biological material

Aromatase (ARO) is an enzyme with potential diagnostic significance. Aberrant expression of aromatase in tissues is associated with a number of pathological conditions, including tumor of the breast, ovary, testes, liver, adrenal cortex and uterus, as well as endometriosis.

Two methods for the highly selective determination of ARO concentration in human tissues by using of two different biosensors co-operating with the surface plasmon resonance imaging technique (SPRI) have been developed. One of the developed biosensors contains immobilised rabbit polyclonal antibody specific for aromatase (Y-ARO), while the other contains immobilized ARO inhibitor-exemestane (E-ARO). Both biosensors specifically bound ARO from analyzed samples. The analytically useful dynamic response range of both biosensors is between 0.3 and 5.0 ng mL−1. The detection limit (3S.D.) of both biosensors is 90 pg mL−1. Standard deviation of both biosensors is 1%. Recoveries of ARO spikes are between 97 and 108% for both biosensors under model conditions and for real samples. Albumin and alkaline phosphatase are tolerated for both biosensors up to 10,000 fold excess.

Endometriosis: a disease that remains enigmatic

Endometriosis, a gynecologic pathology, is defined by the presence of a tissue similar to uterine endometrium, which is located in places other than physiologically appropriate. These endometrial heterotopic islets contain glands and stroma and are functionally capable of responding to exogenous, endogenous, or local hormonal stimuli. Endometriosis affects 8%-10% of women of reproductive age; in 30% of the women, the condition is associated with primary or secondary infertility. In several instances, endometriosis persists as a minimal or mild disease, or it can resolve on its own. Other cases of endometriosis show severe symptomatology that ends when menopause occurs. Endometriosis can, however, reactivate in several postmenopausal women when iatrogenic or endogenous hormones are present. Endometriosis is occasionally accompanied by malignant ovarian tumors, especially endometrioid and clear cell carcinomas. Its pathogenesis is widely debated, and its variable morphology appears to represent a continuum of individual presentations and progressions. Endometriosis has no pathognomonic signs or symptoms; it is therefore difficult to diagnose. Because of its enigmatic etiopathogenesis, there is currently no satisfactory therapy for all patients with endometriosis. Treatments include medications, surgery, or combined therapies; currently, the only procedures that seem to cure endometriosis are hysterectomy and bilateral salpingo-oophorectomy. In this paper, we review the most controversial and enigmatic aspects of this disease.

Role of inflammation and aromatase expression in the eutopic endometrium and its relationship with the development of endometriosis

Epigenetic changes favoring the transcription of the aromatase gene in the endometrium allow endometrial cells to survive in ectopic locations by producing estrogens that spare them from destruction through activated macrophages. Local estrogen production hastens prostaglandin synthesis by stimulating COX-2 activity, thus creating a self-perpetuating sequence of augmented estrogen formation and enhanced inflammation. Repetitive retrograde menstruation reintroduces aromatase-positive endometrial cells endowed with the capacity to implant and invade the peritoneum. In order to control endometriosis, an effective medication must inhibit aromatase, block COX-2, decrease fibrosis and induce amenorrhea. Within this framework, progestins, either alone or in the form of oral contraceptives, appear as first-line treatment for endometriosis owing to their capacity to block enzymes such as aromatase and COX-2.

Pathogenesis and pathophysiology of endometriosis

Originally described over three hundred years ago, endometriosis is classically defined by the presence of endometrial glands and stroma in extrauterine locations. Endometriosis is an inflammatory, estrogen-dependent condition associated with pelvic pain and infertility. This work reviews the disease process from theories regarding origin to the molecular basis for disease sequelae. A thorough understanding of the histopathogenesis and pathophysiology of endometriosis is essential to the development of novel diagnostic and treatment approaches for this debilitating condition.

Estrogen biosynthesis and signaling in endometriosis

Endometriosis is an estrogen-dependent gynecological disease where endometrium-like tissue grows outside uterine cavity. Endometriotic cell proliferation is stimulated by estrogens acting predominantly via their nuclear receptors. Estrogen receptors (ESR1, ESR2) are ligand activated transcription factors whose activation is dependent on the cell-specific dynamic expression of the receptors, on the interacting proteins and on the ligand availability. The different types of endometriotic lesions, peritoneal, deep, and ovarian endometriosis, may respond to estrogens differentially due to differences in the expression of the receptors and interacting proteins, and due to potential differences in the ligand availability regulated by the local estrogen synthesis. This review summarizes the current knowledge of estrogen synthesizing enzymes and estrogen receptors in different types of endometriosis lesions. Further studies are still needed to define the possible differences in steroid metabolism in different types of endometriotic lesions.

New trends for the medical treatment of endometriosis

INTRODUCTION

Endometriosis is a benign sex hormone-dependent gynecological disease, characterized by the presence and growth of endometrial tissue outside the uterus; it affects 10% of women of reproductive age and is associated with infertility and pain. Treatment of endometriosis involves conservative or radical surgery, or medical therapies. The goals for endometriosis treatment may be the relief of pain and/or a successful pregnancy achievement in infertile patients. Treatment must be individualized with a multidisciplinary approach. The classical treatments carry adverse side effects and in some cases a negative impact on quality of life. New agents promise a distinct perspective in endometriosis treatment.

AREAS COVERED

The aim of this paper is to systematically review the literature evidence of new medical treatments for endometriosis, defined as pharmacological treatments not yet commonly available and currently under investigation.

EXPERT OPINION

These new medical therapies would be used associated with surgical treatment and, in the future, will render possible the association of hormone therapy with non-hormonal treatment for endometriosis.

How can macroscopically normal peritoneum contribute to the pathogenesis of endometriosis?

This study indicates that the immunobiology of macroscopically normal peritoneum is relevant to understand the pathogenesis of endometriosis. Peritoneal interleukin 6, interleukin 12, and ferritin were differentially expressed in women with and without endometriosis.

The emerging use of aromatase inhibitors for endometriosis treatment

Endometriosis is defined as the growth of endometrial tissue outside of the uterine cavity. The disease occurs primarily in women of reproductive age but recurrent endometriosis is also detected in post-menopausal women. Regardless of age, endometriosis is associated with pain and reduces the quality of life for millions of women world-wide. Conventional therapies focus on reducing systemic levels of estrogen which results in cessation of endometriotic implant growth and pain symptoms associated with the disease. However, these treatments are not effective in all women and are not without side effects. Based upon the discovery that endometriotic tissue over-expresses aromatase, an enzyme critical for estrogen production, emphasis has been placed upon the use of aromatase inhibitors for the treatment of endometriosis and its associated symptoms. This article will review the rationale behind the use of aromatase inhibitors in treating endometriosis and summarize those studies which have evaluated the use of aromatase inhibitors in the treatment of endometriosis and its associated symptoms.