Urocortin 2 and urocortin 3 in endometriosis: evidence for a possible role in inflammatory response

Biomarkers of endometriosis

Endometriosis is one of the most severe female reproductive disorders, affecting 6-10% of women between 18 and 35. It is a gynaecological condition where endometrial tissue develops and settles outside the uterus. The aetiology of endometriosis is primarily influenced by genetic, epigenetic, and non-genetic variables, making it highly challenging to create a therapeutic therapy explicitly targeting the ectopic tissue. The delay in the treatment is due to the limitations in the diagnostic approaches, which are restricted to invasive techniques such as laparoscopy or laparotomy. This accords to 70% of the women being diagnosed at later stages. By understanding the subject, several treatment medications have been produced to lessen the disease's symptoms. Nevertheless, endometriosis cannot be permanently cured. A viable or persuasive standard screening test for endometriosis must be utilized in a clinical context. A helpful assessment method for the early identification of endometriosis could be biomarkers. A major research priority is the identification of a biomarker that is sensitive and specific enough for detecting endometriosis. The present article has reviewed studies published on the expression of biomarkers of endometriosis. It outlines various biomarkers from different sample types, such as serum/plasma and urine, in addition to tissue. This would provide a non-invasive approach to diagnosing the disease at the initial stages without any harmful repercussions. Future high-throughput advances in science and technology are anticipated to result in the creation of a potent remedy for endometriosis. To achieve successful outcomes, it is necessary to research the discussed biomarkers that demonstrate substantial results extensively.

Expression of HOXA10 Gene in Women with Endometriosis: A Systematic Review

The homeobox A10 (HOXA10) gene is known to be related to endometriosis; however, due to a lack of knowledge/evidence in the pathogenesis of endometriosis, the mechanisms that link HOXA10 to endometriosis still need to be clarified. This review addresses the difference in the expression of the HOXA10 gene in endometriotic women versus non-endometriotic women across populations by country and discusses its influences on women's fertility. An organized search of electronic databases was conducted in Scopus, ScienceDirect, PubMed, and Web of Science. The keywords used were (HOXA10 OR "homeobox A10" OR PL OR HOX1 OR HOX1H OR HOX1.8) AND ("gene expression") AND (endometriosis). The initial search resulted in 623 articles, 10 of which were included in this review. All ten papers included in this study were rated fair in terms of the quality of the studies conducted. The expression of the HOXA10 gene was found to be downregulated in most studies. However, one study provided evidence of the downregulation and upregulation of HOXA10 gene expression due to the localization of endometriotic lesions. Measuring the expression of the HOXA10 gene in women is clinically essential to predicting endometriosis, endometrial receptivity, and the development of pinopodes in the endometrium during the luteal phase.

Possible Correlation between Urocortin 1 (Ucn1) and Immune Parameters in Patients with Endometriosis

The etiology of endometriosis (EMS) has not been clearly elucidated yet, and that is probably the reason why its diagnostic process is frequently long-lasting and inefficient. Nowadays, the non-invasive diagnostic methods of EMS are still being sought. Our study aimed to assess the serum and peritoneal fluid levels of urocortin 1 (Ucn1) in patients with EMS and healthy women. Moreover, considering the immune background of the disease, the association between Ucn1 and several immune parameters was studied in both groups. We found that the serum Ucn1 level was significantly upregulated in women with EMS compared to healthy patients. Moreover, higher serum Ucn1 levels tended to correspond with more advanced stages of the disease (p = 0.031). Receiver operating characteristic (ROC) analysis revealed that based on serum Ucn1 levels, it is possible to distinguish deep infiltrating endometriosis (DIE) from among other EMS types. Together, these results indicate Ucn1 as a possible promising biomarker of EMS: however, not in isolation, but rather to enhance the effectiveness of other diagnostic methods.

The urocortin peptides: biological relevance and laboratory aspects of UCN3 and its receptor

The urocortins are polypeptides belonging to the corticotropin-releasing hormone family, known to modulate stress responses in mammals. Stress, whether induced physically or psychologically, is an underlying cause or consequence of numerous clinical syndromes. Identifying biological markers associated with the homeostatic regulation of stress could provide a clinical laboratory approach for the management of stress-related disorders. The neuropeptide, urocortin 3 (UCN3), and the corticotropin-releasing hormone receptor 2 (CRHR2) constitute a regulatory axis known to mediate stress homeostasis. Dysregulation of this peptide/receptor axis is believed to play a role in several clinical conditions including post-traumatic stress, sleep apnea, cardiovascular disease, and other health problems related to stress. Understanding the physiology and measurement of the UCN3/CRHR2 axis is important for establishing a viable clinical laboratory diagnostic. In this article, we focus on evidence supporting the role of UCN3 and its receptor in stress-related clinical syndromes. We also provide insight into the measurements of UCN3 in blood and urine. These potential biomarkers provide new opportunities for clinical research and applications of laboratory medicine diagnostics in stress management.

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.

The Role of Selected Chemokines in the Peritoneal Fluid of Women with Endometriosis—Participation in the Pathogenesis of the Disease

Endometriosis is a disorder characterized by the presence of endometrial tissue outside the uterine cavity, primarily into the peritoneal cavity. It is known as a complex, chronic inflammatory disease and it is strongly associated with immune dysregulation. Various soluble mediators of the immune and inflammatory responses, including chemokines, play an important role in these processes. The aim of the study was to understand the role of the chemokines MCP-1, MCP-2, MCP-3, MCP-4, MIP-1 α, MIP-1β, eotaxin 2, eotaxin 3, ENA-78, and fractalkine in the development of endometriosis through their assessment in the peritoneal fluid of women with endometriosis. The study group included 58 women with endometriosis who were diagnosed during laparoscopy and then confirmed by histopathology. In 15 women from the reference group, laparoscopic examination demonstrated a normal status of the pelvic organs without any evidence of endometriosis nor inflammation in the peritoneal cavity. The peritoneal fluid of women with endometriosis and of women from the reference group were examined. To determine the concentration of the studied chemokines, enzyme immunoassays for Luminex® platforms were used. In the peritoneal fluid of women with endometriosis, a statistically significant increase in the concentration of MIP-1β, eotaxin 2, eotaxin 3, ENA-78, and fractalkine and a decrease in the concentration of MCP-1, MCP-2, MCP-3, MCP-4, and MIP-1α were observed compared to the reference group. The concentration of these cytokines depended on the severity of the disease. Changes in the concentration of the studied chemokines in the peritoneal fluid of women with endometriosis suggest their participation in the pathogenesis of the disease. The differences in chemokines concentration observed in different stages of endometriosis may be associated with the presence of inflammation in the peritoneal cavity at each step of disease development.

Mucosal biomarkers for endometrial receptivity: A promising yet underexplored aspect of reproductive medicine

Annually, approximately 2 million assisted reproductive technology (ART) procedures are performed worldwide, of which, only ~25% lead to successful delivery. There are two major factors contributing to successful implantation: embryo quality and endometrial receptivity (ER). Although embryo quality might be assessed through morphological and genetic testing, no clinically approved techniques are available to evaluate ER. Mucus in different parts of the female reproductive tract contains many cytokines, chemokines, growth factors, and nucleic acids, which influence and reflect various implantation-related processes. Therefore, the aim of the present review was to summarize available data regarding noninvasively obtained mucosal biomarkers for ER and to investigate their ability to predict the outcome of ART procedures. A broad literature search was performed to define studies related to noninvasive ER assessments. More than 50 biomarkers detectable in endometrial fluid, embryo transfer cannula leftover cells and mucus, menstrual blood, cervicovaginal washings are discussed herein. The remarkable methodological heterogeneity of the reviewed studies complicates the comparison of their results. Nevertheless, certain promising analytical targets may already be identified, such as urocortin, activin A, IL-1β, TNF-α, IP-10, MCP-1, and several oxidative stress biomarkers. The present review contains a collection of currently available mucosal biomarker-related data, which may provide insights for future studies.Abbreviations: ART: assisted reproductive technology; ER: endometrial receptivity; IVF: in vitro fertilization; ICSI: intracytoplasmic sperm injection; IUI: intrauterine insemination; MeSH: Medical Subject Headings; hDP 200: human decidua-associated protein 200; ET: embryo transfer; IL-18: Interleukin-18; LRG: leucine-rich α2-glycoprotein; ROC: receiver operating characteristic; AUC: area under the ROC-curve; LH: luteinizing hormone; LIF: leukemia inhibitory factor; TNF-α: tumor necrosis factor alpha; IFN-γ: interferon γ; MCP-1: monocyte chemoattractant protein-1; VEGF: vascular endothelial growth factor; SOD: superoxide dismutase; CAT: catalase; LPO: lipid peroxidation; TTG: total thiol groups; TAP: total antioxidant power; CE: chronic endometritis.

Relationship Between Dairy Products Intake and Risk of Endometriosis: A Systematic Review and Dose-Response Meta-Analysis

Objective: Diet lifestyle can influence the risk of endometriosis. Therefore, we conducted a systematic meta-analysis to investigate the association between dairy products and the risk of endometriosis. Besides, we performed a dose-response meta-analysis to evaluate the amount of dairy intake affecting the risk of endometriosis.

Methods: Relevant studies were searched from Pubmed, Embase databases, Cochrane Library, and Web of Science from the inception to November 6th, 2020. Also, the dose-response meta-analysis was conducted. All the pooled results were performed by risk ratios (RRs).

Results: Finally, seven high-quality studies were included in the present meta-analysis. Total dairy intake was inversely associated with the risk of endometriosis, and the risk of endometriosis tended to decrease with a decrease in the risk of endometriosis when dairy products intake was over 21 servings/week (RR 0.87, 95% CI 0.76–1.00; p_{non−linearity} = 0.04). Similarly, people who consumed more than 18 servings of high-fat dairy products per week had a reduced risk of endometriosis (RR 0.86, 95% CI 0.76–0.96). When stratified-analyses were conducted based on specific dairy product categories, it indicated that people with high cheese intake might have a reduced risk of endometriosis (RR 0.86, 95% CI 0.74–1.00). Other specific dairy products such as whole milk (RR 0.90, 95% CI 0.72–1.12), reduced-fat/skim milk (RR 0.83, 95% CI 0.50–1.73), ice cream (RR 0.83, 95% CI 0.50–1.73), and yogurt (RR 0.83, 95% CI 0.62–1.11) have not shown significant evidence of an association with the risk of endometriosis. However, there is a higher risk of endometriosis in the females with high butter intake compared to females with low butter intake (1.27, 95% CI 1.03–1.55).

Conclusions: Overall, dairy products intake was associated with a reduction in endometriosis, with significant effects when the average daily intake ≥3 servings. When analyzed according to the specific type of dairy product, it was shown that females with higher high-fat dairy and cheese intake might have a reduced risk of endometriosis. However, high butter intake might be associated to the increased risk of endometriosis. More future studies are needed to validate and add to this finding.

Current biomarkers for the detection of endometriosis

A clinically reliable non-invasive test for endometriosis is expected to reduce the diagnostic delay. Although varieties of biomarkers have been investigated for decades, and cancer antigen-125, cancer antigen-199, interleukin-6, and urocortin were the most studied ones among hundreds of biomarkers, no clinically reliable biomarkers have been confirmed so far. Some emerging technologies including “omics” technologies, molecular imaging techniques, and microRNAs are promising in solving these challenges, but their utility to detect endometriosis has yet to be verified. New combinations of researched indicators or other non-invasive methods and further exploration of the emerging technologies may be new targets and future research hotspots for non-invasive diagnosis of endometriosis. In conclusion, researches of biomarkers for the detection of endometriosis are still ongoing and may benefit from novel molecular biology, bioinformatics methods and a combination of more diverse monitoring methods. Though it will be a daunting task, the identification of a specific set of diagnostic biomarkers will undoubtedly improve the status of endometriosis.

Endometriosis: New Perspective for the Diagnosis of Certain Cytokines in Women and Adolescent Girls, as Well as the Progression of Disease Outgrowth: A Systematic Review

Endometriosis is a common chronic gynecological disorder that undoubtedly impacts on quality of life, and is one of the more complex and mysterious illnesses of our century, which is associated with the improper growth of endometrial tissue outside of the uterine cavity. This pathologically implanted tissue can be found most frequently in the minor pelvis, but also in the peritoneal cavity, and can affect many organs, leading to chronic pelvic pain syndrome, infertility, and dysmenorrhea. Endometrial tissue is a particularly dynamic tissue that has a direct impact on the progression of the disease, with altered immunity, as well as cytokine storms within the metaplastic endometriotic site, as possible key factors. Currently, diagnosis of this mysterious chronic illness relies on performing a laparoscopic procedure with tissue sampling. One of the most troublesome outcomes of this unintended progression is that we lack any specific, sensitive, non-invasive diagnostic tools. Currently, the vast majority of regime stewardship options rely on anti-contraceptive drugs, or other remedies that suppress the release of estrogen through the gonads-although in most clinical trials, endometriosis is a chronic progressive disorder that depends mostly on the high concentration of estrogen. Moreover, many specific trials have demonstrated that the eutopic endometrial cells in individuals with endometriosis remain much more resistant to the immunological annihilation process caused by certain elements of the immune system. Nevertheless, eutopic endometrial cells have the potential to similarly escalate the expression of aromatase receptors on the surface of the pathological cells, which in the final cascade cause an increase in the concentration of estrogen, as well as other inflammatory proteins that contribute to pathological outgrowth. Data reveal occurrence among first-degree relatives, suggesting that the specific cascade could be related to inherited as well as epigenetic (acquired) mechanisms. In women with the disease, confirmed by laparoscopic procedures, diagnosis of endometriosis can be established also via detection by gene polymorphism in the genes which are responsible for responsible for the detoxification phase of estrogen receptors and other immunomodulator components. A recent publication aims to reveal a new prospect for the non-invasive diagnosis, detection, and estimation of certain biomarkers for much more specific investigation of the disease's progression.

Functional maturation of immature β cells: A roadblock for stem cell therapy for type 1 diabetes

Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disease caused by the specific destruction of pancreatic islet β cells and is characterized as the absolute insufficiency of insulin secretion. Current insulin replacement therapy supplies insulin in a non-physiological way and is associated with devastating complications. Experimental islet transplantation therapy has been proven to restore glucose homeostasis in people with severe T1DM. However, it is restricted by many factors such as severe shortage of donor sources, progressive loss of donor cells, high cost, etc. As pluripotent stem cells have the potential to give rise to all cells including islet β cells in the body, stem cell therapy for diabetes has attracted great attention in the academic community and the general public. Transplantation of islet β-like cells differentiated from human pluripotent stem cells (hPSCs) has the potential to be an excellent alternative to islet transplantation. In stem cell therapy, obtaining β cells with complete insulin secretion in vitro is crucial. However, after much research, it has been found that the β-like cells obtained by in vitro differentiation still have many defects, including lack of adult-type glucose stimulated insulin secretion, and multi-hormonal secretion, suggesting that in vitro culture does not allows for obtaining fully mature β-like cells for transplantation. A large number of studies have found that many transcription factors play important roles in the process of transforming immature to mature human islet β cells. Furthermore, PDX1, NKX6.1, SOX9, NGN3, PAX4, etc., are important in inducing hPSC differentiation in vitro. The absent or deficient expression of any of these key factors may lead to the islet development defect in vivo and the failure of stem cells to differentiate into genuine functional β-like cells in vitro. This article reviews β cell maturation in vivo and in vitro and the vital roles of key molecules in this process, in order to explore the current problems in stem cell therapy for diabetes.

The Link Between Stress and Endometriosis: from Animal Models to the Clinical Scenario

There is strong evidence from humans and animal models showing that abnormal functioning of the hypothalamic-pituitary-adrenal (HPA) axis and/or the inflammatory response system disrupts feedback regulation of both neuroendocrine and immune systems, contributing to disease. Stress is known to affect the physiology of pelvic organs and to disturb the HPA axis leading to chronic, painful, inflammatory disorders. A link between stress and disease has already been documented for many chronic conditions. Endometriosis is a complex chronic gynecological disease associated with severe pelvic pain and infertility that affects 10% of reproductive-aged women. Patients report the negative impact of endometriosis symptoms on quality of life, work/study productivity, and personal relationships, which in turn cause high levels of psychological and emotional distress. The relationship between stress and endometriosis is not clear. Still, we have recently demonstrated that stress increases the size and severity of the lesions as well as inflammatory parameters in an animal model. Furthermore, the "controllability" of stress influences the pathophysiology in this model, offering the possibility of using stress management techniques in patients. The crosstalk between stress-inflammation-pain through HPA axis activity indicates that stress relief should alleviate inflammation and, in turn, decrease painful responses. This opens up the opportunity of altering brain-body-brain pathways as potential new therapeutic option for endometriosis. The goal of this review is to gather the research evidence regarding the interaction between stress (psychological and physiological) and the development and progression of endometriosis on the exacerbation of its symptoms with the purpose of proposing new lines of emerging research and possible treatment modalities for this still incurable disease.

Progress in understanding the roles of Urocortin3 (UCN3) in the control of appetite from studies using animal models

Urocortin3 (UCN3), the newest member of corticotrophin releasing hormone (CRH) family polypeptides, is an anorexic factor discovered in 2001, which has a strong inhibitory effect on animal appetite regulation. UCN3 is widely distributed in various tissues of animals and has many biological functions. Based on the research progress of UCN3 on mammals and non-mammals, this paper summarized the discovery, tissue distribution, appetite regulation and mechanism of UCN3 in animals, in order to provide a reference for feeding regulation and growth in mammals and fish in further research and production.

Anti-inflammatory cytokines in endometriosis

Although the pathogenesis of endometriosis is not fully understood, it is often considered to be an inflammatory disease. An increasing number of studies suggest that differential expression of anti-inflammatory cytokines (e.g., interleukin-4 and -10, and transforming growth factor-β1) occurs in women with endometriosis, including in serum, peritoneal fluid and ectopic lesions. These anti-inflammatory cytokines also have indispensable roles in the progression of endometriosis, including by promoting survival, growth, invasion, differentiation, angiogenesis, and immune escape of the endometriotic lesions. In this review, we provide an overview of the expression, origin, function and regulation of anti-inflammatory cytokines in endometriosis, with brief discussion and perspectives on their future clinical implications in the diagnosis and therapy of the disease.

Urocortin Expression in Endometriosis: A Systematic Review

Urocortin (UCN) is a neuropeptide that belongs to the corticotrophin-releasing hormone family and is expressed by eutopic and ectopic human endometria. The past years, this expression has been thoroughly investigated in the field of endometriosis. The objective of this systematic review is to accumulate current evidence related to the expression of UCN in tissue and blood samples of patients suffering from endometriosis. Literature search was designed accord- ing to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and primarily conducted using the Medline (1966-2018), Scopus (2004-2018), EMBASE (1947-2018) and Clinicaltrials.gov (2008- 2018) databases, along with the reference lists of electronically retrieved full-text papers. Overall, eight studies were retrieved. Current evidence suggests that the expression of UCN is increased in patients with ovarian endometriomas and that its levels may correlate with the severity of the disease. The diagnostic efficacy of UCN1 plasma levels was evaluated in three studies. Two of them suggested that the sensitivity and specificity of the method may reach, and even exceed, 80%. However, the wide variation in outcome reporting and outcome reporting measures in endome- triosis among the included studies precludes meta-analysis of available data. Therefore, although UCN seems to be a promising biomarker for the identification and follow-up of patients that suffer from endometriosis, more studies are needed to reach firm conclusions with respect to its predictive accuracy.

The crosstalk between endometrial stromal cells and macrophages impairs cytotoxicity of NK cells in endometriosis by secreting IL-10 and TGF-β

The dysfunction of NK cells in women with endometriosis (EMS) contributes to the immune escape of menstrual endometrial fragments refluxed into the peritoneal cavity. The reciprocal communications between endometrial stromal cells (ESCs) and lymphocytes facilitate the development of EMS. However, the mechanism of these communications on cytotoxicity of natural killer (NK) cells in endometriotic milieus is still largely unknown. To imitate the local immune microenvironment, the co-culture systems of ESCs from patients with EMS and monocyte-derived macrophages or of ESCs, macrophages and NK cells were constructed. The cytokine levels in the co-culture unit were evaluated by ELISA. The expression of functional molecules in NK cells was detected by flow cytometry (FCM). The NK cell behaviors in vitro were analyzed by cell counting kit-8 and cytotoxic activation assays. After incubation with ESCs and macrophages, the expression of CD16, NKG2D, perforin and IFN-γ, viability and cytotoxicity of NK cells were significantly downregulated. The secretion of interleukin (IL)-1β, IL-10 and transforming growth factor (TGF)-β in the co-culture system of ESCs and macrophages was increased. Exposure with anti-IL-10 receptor β neutralizing antibody (αhIL-10Rβ) or αTGF-β could partly reverse these effects of ESCs and macrophages on NK cells in vitro These results suggest that the interaction between macrophages and ESCs downregulates cytotoxicity of NK cells possibly by stimulating the secretion of IL-10 and TGF-β, and may further trigger the immune escape of ectopic fragments and promote the occurrence and the development of EMS.

Intraperitoneal injection urocortin-3 reduces the food intake of Siberian sturgeon (Acipenser baerii)

Urocortin-3 (UCN3), one of the corticotropin releasing factor (CRF) family peptides, which was discovered in 2001, has a variety of biological functions. However, the researches of UCN3 in fish were scarce. In order to understand whether UCN3 play a role in regulating food intake in fish, we first cloned the ucn3 cDNAs sequence of Siberian sturgeon (Acipenser baerii Brandt), and investigated the ucn3 mRNA levels in 11 tissues. The Siberian sturgeon ucn3 cDNA sequence was 1044bp, including an open reading frame (ORF) of 447bp that encoded 148 amino acids with a mature peptide of 40 amino acids, a 5'-terminal untranslated region (5'-UTR) of 162bp and a 3'-terminal untranslated region (3'-UTR) of 435bp. The result of tissue distribution showed that ucn3 widely distributed in 11 tissues with highest expression in brain. We also assessed the effects of periprandial (pre- and post-feeding), fasting and re-feeding on ucn3 mRNAs abundance in brain. The results showed the expression of ucn3 mRNA in brain was significantly elevated after feeding, decreased after fasting 17 days and increased after re-feeding. To further investigate the food intake role of UCN3 in Siberian sturgeon, we performed intraperitoneal (i.p.) injection of Siberian sturgeon UCN3 (SsUCN3) with three doses (60, 120 or 240ng/g) and recorded the food intake. Acute and chronic i.p. injection SsUCN3 reduced the food intake in a dose-dependent pattern. In conclusion, this study indicates that SsUCN3 acts as a satiety factor to inhibit the food intake of Siberian sturgeon.

Urocortin and corticotrophin-releasing hormone receptor type 2 mRNA are highly expressed in deep infiltrating endometriotic lesions

Ovarian endometrioma (OMA) and deep infiltrating endometriosis (DIE) are the most severe forms of endometriosis, but different pathogenetic mechanisms and clinical symptoms distinguish these two forms. Corticotrophin-releasing hormone (CRH) and urocortin (Ucn) are endometrial neuropeptides involved in tissue differentiation and inflammation. The expression of CRH, Ucn, Ucn2, CRH-receptors (type-1 and type-2) and inflammatory enzymes phospholipase-A2 group IIA (PLA2G2A) and cycloxygenase-2 (COX2) were evaluated in OMA (n = 22) and DIE (n = 26). The effect of CRH or Ucn on COX2 mRNA expression was evaluated in cultured human endometrial stromal cells. In DIE lesions, CRH, Ucn and CRH-R2 mRNA levels were significantly higher than in OMA (P < 0.01, P < 0.001 and P < 0.05, respectively); DIE lesions showed a higher expression of COX2 (P < 0.01) and PLA2G2A (P < 0.05) mRNA than OMA, which was positively correlated with CRH-R2 mRNA expression (P < 0.05). Intense immunostaining for CRH and Ucn was shown in DIE. Treatment of cultured endometrial stromal cells with Ucn significantly increased COX2 mRNA expression (P < 0.01); this effect was reversed by the CRH-R2 antagonist astressin-2B. In DIE, DIE lesions highly express neuropeptide and enzyme mRNAs, supporting a strong activation of inflammatory pathways.

Increased circulating urocortin-3 levels is associated with polycystic ovary syndrome

This study was aimed to compare serum urocortin-3 (UCN3) levels in women with polycystic ovary syndrome (PCOS) and healthy women, and establish what role UCN3 levels play in PCOS. Fifty-two patients with PCOS and 55 healthy women were included in the study, matched for age and body mass index. Fasting blood glucose (FBG), insulin, hs-CRP, UCN3 and free-testosterone levels of the all participants were measured. HOMA-IR was used to calculate the insulin resistance. Circulating UCN3 levels were significantly increased in women with PCOS than in control subjects (54.49 ± 5.77 versus 51.28 ± 5.86 pmol/l, p = 0.005). Serum insulin, hs-CRP and HOMA-IR levels were higher in women with PCOS than in control group. UCN3 levels positively correlated with hs-CRP in PCOS group (r = 0.391, p = 0.004). Receiver operating characteristic (ROC) curve analysis showed that the area under the ROC curves were 0.732 (95% CI 0.634-0.830, p < 0.001) for UCN3 levels. The optimal cut-off value of UCN3 for detecting PCOS was ≥51.46 pmol/l, at which the sensitivity was 75% and specificity was 68%. Our results suggest that there is a potential link between PCOS and UCN3 levels. The results of this study support the presence of increased UCN3 levels for the association of inflammation with PCOS.

Serum markers for the noninvasive diagnosis of endometriosis

Endometriosis is a disease that affects millions of women worldwide and its diagnosis is still challenging. Medical history, symptoms together with imaging data may address the correct diagnosis, but the gold standard remains laparoscopic assessment with histological confirmation. The development of serum markers as diagnostic tools for endometriosis may allow a prompt and noninvasive diagnosis. Several serum biomarkers have been investigated over the years, but none of these have shown a clinical utility and nowadays the more realistic diagnostic biomarker consists in a panel of biomarkers. The recent introduction of new technologies such as genomics and proteomics may represent the future perspective of endometriosis diagnosis.

Increased alcohol consumption in urocortin 3 knockout mice is unaffected by chronic inflammatory pain

AIMS

Stress neurocircuitry may modulate the relationship between alcohol drinking and chronic pain. The corticotropin-releasing factor (CRF) system is crucial for regulation of stress responses. The current study aimed to elucidate the role of the endogenous CRF ligand Urocortin 3 (Ucn3) in the relationship between alcohol drinking behavior and chronic pain using a genetic approach.

METHODS

Ucn3 (KO) and wildtype (WT) littermates were subjected to a 24-h access drinking procedure prior to and following induction of chronic inflammatory pain.

RESULTS

Ucn3 KO mice displayed significantly increased ethanol intake and preference compared with WT across the time course. There were no long-term effects of chronic pain on alcohol drinking behavior, regardless of genotype, nor any evidence for alcohol-induced analgesia.

CONCLUSION

The increased drinking in Ucn3 KO supports a role for this peptide in alcohol-related behavior. These data suggest the necessity for more research exploring the relationship between alcohol drinking, chronic pain and the CRF system in rodent models.

Molecular aspects of development and regulation of endometriosis

Endometriosis is a common and painful condition affecting women of reproductive age. While the underlying pathophysiology is still largely unknown, much advancement has been made in understanding the progression of the disease. In recent years, a great deal of research has focused on non-invasive diagnostic tools, such as biomarkers, as well as identification of potential therapeutic targets. In this article, we will review the etiology and cellular mechanisms associated with endometriosis as well as the current diagnostic tools and therapies. We will then discuss the more recent genomic and proteomic studies and how these data may guide development of novel diagnostics and therapeutics. The current diagnostic tools are invasive and current therapies primarily treat the symptoms of endometriosis. Optimally, the advancement of "-omic" data will facilitate the development of non-invasive diagnostic biomarkers as well as therapeutics that target the pathophysiology of the disease and halt, or even reverse, progression. However, the amount of data generated by these types of studies is vast and bioinformatics analysis, such as we present here, will be critical to identification of appropriate targets for further study.

Estrogens downregulate urocortin 2 expression in rat uterus

Urocortin 2 (Ucn2) is a member of the corticotropin-releasing factor peptide family and is expressed by various tissues, including reproductive tissues such as the uterus, ovary, and placenta. However, the regulatory mechanisms of Ucn2 expression and the physiological significance of Ucn2 in these tissues remain unclear. We previously showed that passive immunization of immature female rats by i.p. injection of anti-Ucn2 IgG induces earlier onset of puberty. Therefore, this study was designed to clarify the site and regulatory mechanisms of Ucn2 expression in the uterus. Expression levels of Ucn2 mRNA in the uterus were higher in immature (2- and 4-week-old) and aged (17-month-old) rats than in mature (9-week-old) rats in the proestrus phase. In 9-week-old rats, mRNA expression levels and contents in the uterus were lower in the proestrus phase than in the diestrus phase, while plasma Ucn2 concentrations did not differ between the two phases. Ucn2-like immunoreactivitiy was detected in the endometrial gland epithelial cells of the uterus. S.c. injection of estradiol benzoate or an estrogen receptor α (ERα) agonist significantly reduced mRNA expression levels and contents of Ucn2 in the uterus when compared with vehicle-injected ovariectomized rats. By contrast, estradiol benzoate increased Ucn2 mRNA expression levels in the lung. Thus, estrogens downregulate Ucn2 expression in the uterus in a tissue-specific manner, and Ucn2 may play a role in the regulatory mechanisms of maturation of the uterus through ERα and estrous cycle.

Evaluation of mean platelet volume, neutrophil/lymphocyte ratio and platelet/lymphocyte ratio in advanced stage endometriosis with endometrioma

OBJECTIVE

We compared the preoperative values of mean platelet volume (MPV) and peripheral systemic inflammatory response (SIR) markers (neutrophil/lymphocyte ratio and platelet/lymphocyte ratio) between patients with advanced-stage (stage 3/4) endometriosis having endometrioma (OMA) and patients with a non-neoplastic adnexal mass other than endometrioma (non-OMA).

MATERIAL AND METHODS

Patients who underwent operations with the pre-diagnosis of infertility or adnexal mass and who underwent laparoscopic tubal ligation were included.

RESULTS

Haemoglobin levels, leucocyte count, platelet count, neutrophil count and lymphocyte count were not significantly different between patients with advanced stage endometriosis having OMA, patients with non-OMA and patients in the control group (p=0.970, p=0.902, p=0.373, p=0.501 and p=0.463, respectively). Patients with stage 3/4 endometriosis having OMA, patients with non-OMA and control patients were also not significantly different in terms of MPV (p=0.836), neutrophil/lymphocyte ratio (NLR) (p=0.555) and platelet/lymphocyte ratio (PLR) (p=0.358). Preoperative cancer antigen 125 (Ca-125) levels were significantly higher in patients with OMA (p=0.006). Mean size of the OMAs was significantly lower than non-OMAs (p=0.000).

CONCLUSION

It is very important to determine advanced stage endometriosis and OMAs during preoperative evaluation in order to inform patients and plan an appropriate surgical approach. We demonstrate that MPV, NLR and PLR values are not useful for this purpose in patients with advanced stage endometriosis that are proven to develop severe inflammation at either the cellular or molecular level.

Endometrioma: From Pathogenesis to Clinical Management

An endometrioma (OMA) is the localization of endometriosis in ovary, and it most often develops as a cyst. The pathogenesis of OMA is still an open question and controversial; a cystic hemorrhagic corpus luteum may be a prerequisite, occurring as a transition to an endometriotic cyst. Inversion and progressive invagination of the ovarian cortex after the accumulation of menstrual debris derived from bleeding of superficial endometriotic implants, located on the ovarian surface and adherent to the peritoneum, is another hypothesis. Gene studies show that WNT4 and FN1 are predisposing genes for OMA development. A role of environmental toxicants in the development of OMA is also under investigation; dioxins and dioxin-like compounds (DLCs), interacting with steroid receptors, are possible factors. Even if women with endometriosis have a 1.5 times greater lifetime risk to develop an ovarian carcinoma, an OMA is not to be considered a preneoplastic lesion.

The clinical management of OMAs is complex and should be individualized. Ultrasounds and magnetic resonance imaging (MRI) are sensitive but not specific for diagnosis. Treatment is influenced by patient age, desire for pregnancy, pain severity, cyst dimensions and characteristics (unilateral/bilateral), coexistence of deep endometriosis, previous gynecological or obstetrical history and previous surgery. Laparoscopic surgery is considered the treatment of choice in cases of infertile patients with a large OMA or pain, and in patients not responding to medical therapy. It should be performed with proper techniques by trained surgeons to decrease the damage to the remaining ovarian tissue, and to maintain the ovarian reserve after surgery. A medical hormonal and nonhormonal treatment is used for asymptomatic and/or pain-associated OMA (progestins, estroprogestins and antiinflammatory drugs). Considering the relative high recurrence rate after surgery, a medical treatment should be offered.

Interplay between Misplaced Müllerian-Derived Stem Cells and Peritoneal Immune Dysregulation in the Pathogenesis of Endometriosis

In the genetic regulation of Müllerian structures development, a key role is played by Hoxa and Wnt clusters, because they lead the transcription of different genes according to the different phases of the organogenesis, addressing correctly cell-to-cell interactions, allowing, finally, the physiologic morphogenesis. Accumulating evidence is suggesting that dysregulation of Wnt and/or Hox genes may affect cell migration during organogenesis and differentiation of Müllerian structures of the female reproductive tract, with possible dislocation and dissemination of primordial endometrial stem cells in ectopic regions, which have high plasticity to differentiation. We hypothesize that during postpubertal age, under the influence of different stimuli, these misplaced and quiescent ectopic endometrial cells could acquire new phenotype, biological functions, and immunogenicity. So, these kinds of cells may differentiate, specializing in epithelium, glands, and stroma to form a functional ectopic endometrial tissue. This may provoke a breakdown in the peritoneal cavity homeostasis, with the consequent processes of immune alteration, documented by peripheral mononuclear cells recruitment and secretion of inflammatory cytokines in early phases and of angiogenic and fibrogenic cytokines in the late stages of the disease.

Posttranslational processing of human and mouse urocortin 2: characterization and bioactivity of gene products

Mouse (m) and human (h) urocortin 2 (Ucn 2) were identified by molecular cloning strategies and the primary sequence of their mature forms postulated by analogy to closely related members of the corticotropin-releasing factor (CRF) neuropeptide family. Because of the paucity of Ucn 2 proteins in native tissues, skin, muscle, and pancreatic cell lines were transduced with lentiviral constructs and secretion media were used to isolate and characterize Ucn 2 products and study processing. Primary structures were assigned using a combination of Edman degradation sequencing and mass spectrometry. For mUcn 2, transduced cells secreted a 39 amino acid peptide and the glycosylated prohormone lacking signal peptide; both forms were C-terminally amidated and highly potent to activate the type 2 CRF receptor. Chromatographic profiles of murine tissue extracts were consistent with cleavage of mUcn 2 prohormone to a peptidic form. By contrast to mUcn 2, mammalian cell lines transduced with hUcn 2 constructs secreted significant amounts of an 88 amino acid glycosylated hUcn 2 prohormone but were unable to further process this molecule. Similarly, WM-266-4 melanoma cells that express endogenous hUcn 2 secreted only the glycosylated prohormone lacking the signal peptide and unmodified at the C terminus. Although not amidated, hUcn 2 prohormone purified from overexpressing lines activated CRF receptor 2. Hypoxia and glycosylation, paradigms that might influence secretion or processing of gene products, did not significantly impact hUcn 2 prohormone cleavage. Our findings identify probable Ucn 2 processing products and should expedite the characterization of these proteins in mammalian tissues.

Endometriosis, a disease of the macrophage

Endometriosis, a common cause of pelvic pain and female infertility, depends on the growth of vascularized endometrial tissue at ectopic sites. Endometrial fragments reach the peritoneal cavity during the fertile years: local cues decide whether they yield endometriotic lesions. Macrophages are recruited at sites of hypoxia and tissue stress, where they clear cell debris and heme-iron and generate pro-life and pro-angiogenesis signals. Macrophages are abundant in endometriotic lesions, where are recruited and undergo alternative activation. In rodents macrophages are required for lesions to establish and to grow; bone marrow-derived Tie-2 expressing macrophages specifically contribute to lesions neovasculature, possibly because they concur to the recruitment of circulating endothelial progenitors, and sustain their survival and the integrity of the vessel wall. Macrophages sense cues (hypoxia, cell death, iron overload) in the lesions and react delivering signals to restore the local homeostasis: their action represents a necessary, non-redundant step in the natural history of the disease. Endometriosis may be due to a misperception of macrophages about ectopic endometrial tissue. They perceive it as a wound, they activate programs leading to ectopic cell survival and tissue vascularization. Clearing this misperception is a critical area for the development of novel medical treatments of endometriosis, an urgent and unmet medical need.

Proteomic analysis of menstrual blood

Menstruation is the expulsion of the endometrial lining of the uterus following a nearly month long preparation for embryo implantation and pregnancy. Increasingly, the health of the endometrium is being recognized as a critical factor in female fertility, and proteomes and transcriptomes from endometrial biopsies at different stages of the menstrual cycle have been studied for both diagnostic and therapeutic purposes (1 Kao, L. C., et al. 2003 Endocrinology 144, 2870-2881; Strowitzki, Tet al. 2006 Hum. Reprod. Update 12, 617-630; DeSouza, L., et al. 2005 Proteomics 5, 270-281). Disorders of the uterus ranging from benign to malignant tumors, as well as endometriosis, can cause abnormal menstrual bleeding and are frequently diagnosed through endometrial biopsy (Strowitzki, Tet al. 2006 Hum. Reprod. Update 12, 617-630; Ferenczy, A. 2003 Maturitas 45, 1-14). Yet the proteome of menstrual blood, an easily available noninvasive source of endometrial tissue, has yet to be examined for possible causes or diagnoses of infertility or endometrial pathology. This study employed five different methods to define the menstrual blood proteome. A total of 1061 proteins were identified, 361 were found by at least two methods and 678 were identified by at least two peptides. When the menstrual blood proteome was compared with those of circulating blood (1774 proteins) and vaginal fluid (823 proteins), 385 proteins were found unique to menstrual blood. Gene ontology analysis and evaluation of these specific menstrual blood proteins identified pathways consistent with the processes of the normal endometrial cycle. Several of the proteins unique to menstrual blood suggest that extramedullary uterine hematopoiesis or parenchymal hemoglobin synthesis may be occurring in late endometrial tissue. The establishment of a normal menstrual blood proteome is necessary for the evaluation of its usefulness as a diagnostic tool for infertility and uterine pathologies. Identification of unique menstrual blood proteins should aid the forensic community in distinguishing menstrual blood from circulating blood.