Effect of GnRH analogues on apoptosis and expression of Bcl-2, Bax, Fas and FasL proteins in endometrial epithelial cell cultures from patients with endometriosis and controls

Hormonal Therapies before in vitro fertilization in women with endometriosis: The Minotaur's Labyrinth and the Ariadne's Thread

Endometriosis-related infertility is one of the most debated topics in reproductive medicine. In recent years, prolonged pre-cycle hormonal regimens gained attention as a mean of improving the assisted reproduction technologies (ART) success rates in endometriosis patients. GnRH agonists, dienogest, medroxyprogesterone acetate, and aromatase inhibitors are the most studied medications. Conflicting results and a high risk of bias exist in almost all of the conducted studies in the field. However, current evidence suggests that pre-cycle treatment with GnRH agonists may be beneficial for patients with stage III/IV endometriosis. Dienogest and medroxyprogesterone acetate-based progestin-primed ovarian stimulation protocol was shown to be comparable to the prolonged GnRH agonists protocol. Finally, aromatase inhibitors seem to be of limited benefit to the assisted reproductive outcomes of endometriosis patients. Although it is challenging to draw any clinical conclusions, pre-cycle hormonal treatments seem to be best indicated in endometriosis patients who had previously failed ART treatment.

Immune pathway through endometriosis to ovarian cancer

Endometriosis is an estrogen-dependent inflammatory disease, defined by the presence of functional endometrial tissue outside of the uterine cavity. This disease is one of the main gynecological diseases, affecting around 10%-15% women and girls of reproductive age, being a common gynecologic disorder. Although endometriosis is a benign disease, it shares several characteristics with invasive cancer. Studies support that it has been linked with an increased chance of developing endometrial ovarian cancer, representing an earlier stage of neoplastic processes. This is particularly true for women with clear cell carcinoma, low-grade serous carcinoma and endometrioid. However, the carcinogenic pathways between both pathologies remain poorly understood. Current studies suggest a connection between endometriosis and endometriosis-associated ovarian cancers (EAOCs) via pathways associated with oxidative stress, inflammation, and hyperestrogenism. This article aims to review current data on the molecular events linked to the development of EAOCs from endometriosis, specifically focusing on the complex relationship between the immune response to endometriosis and cancer, including the molecular mechanisms and their ramifications. Examining recent developments in immunotherapy and their potential to boost the effectiveness of future treatments.

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.

Molecular Mechanisms of Endometriosis Revealed Using Omics Data

Endometriosis is a gynecological disorder prevalent in women of reproductive age. The primary symptoms include dysmenorrhea, irregular menstruation, and infertility. However, the pathogenesis of endometriosis remains unclear. With the advent of high-throughput technologies, various omics experiments have been conducted to identify genes related to the pathophysiology of endometriosis. This review highlights the molecular mechanisms underlying endometriosis using omics. When genes identified in omics experiments were compared with endometriosis disease genes identified in independent studies, the number of overlapping genes was moderate. However, the characteristics of these genes were found to be equivalent when functional gene set enrichment analysis was performed using gene ontology and biological pathway information. These findings indicate that omics technology provides invaluable information regarding the pathophysiology of endometriosis. Moreover, the functional characteristics revealed using enrichment analysis provide important clues for discovering endometriosis disease genes in future research.

Efficacy of long-term pituitary down-regulation pretreatment prior to in vitro fertilization in infertile patients with endometriosis: A meta-analysis

Controversial conclusions have been made in previous studies regarding the influence of ultra-long gonadotropin-releasing hormone agonist (GnRH-a) in the reproductive outcomes of women with endometriosis who are undergoing in vitro fertilization/ intracytoplasmic sperm injection embryo transfer (IVF/ICSI-ET). An electronic search was conducted through PubMed, Embase, Cochrane Library, Web of Science, Elsevier ScienceDirect and Medline from inception until 10 September 2022. Only randomized studies were included. After the selection process, seven articles were eventually included in the meta-analysis. The pooling of the results showed the adverse effect of ultra-long protocol in terms of live birth rate (risk ratio (RR) = 0.53, 95% confidence intervals (CI): 0.31-0.9, P=0.02) and fertilization rate (RR = 1.18, 95% CI: 1.02-1.36, P=0.02). There was no statistical significance between the ultra-long protocol and long protocol of the rest outcome Indicators. The findings of this meta-analysis suggest that ultra-long GnRH-a does not appear to improve the results of IVF/ICSI treatment outcomes in patients with endometriosis.

Controlled ovarian stimulation for endometriosis patients with ultra-long GnRH-agonist or GnRH-antagonist protocols: A retrospective study by propensity score matching

OBJECTIVES

Although in vitro fertilization with embryo transfer is the most effective treatment for infertile patients with endometriosis, ovarian stimulation protocols are controversial.

STUDY DESIGN

We recruited 639 patients with endometriosis from January 2016 to June 2020; 111 and 528 patients were treated with the gonadotropin-releasing hormone (GnRH) antagonist and ultra-long GnRH agonist protocols, respectively. Potential baseline differences between the regimens were adjusted by propensity score matching. Clinical and laboratory data, including the cumulative clinical pregnancy rate (CCPR) and cumulative live birth rate (CLBR), were compared.

RESULTS

Ovulation induction required significantly longer use of gonadotropins in the GnRH agonist group. However, the GnRH agonist group had a lower starting dose of gonadotropin (all p < 0.05). Furthermore, significantly lower clinical pregnancy, implantation, and live birth rates were observed in the GnRH antagonist group receiving fresh assisted reproductive technology cycles (all p < 0.05); however, pregnancy outcomes using the subsequent freeze-thaw cycles for the same oocyte retrieval were not significantly different. CCPR and CLBR for the oocyte retrieval cycles of the antagonist and ultra-long agonist protocols were similar. The ultra-long agonist protocol resulted in more favorable implantation of fresh embryos and improved clinical outcomes of the fresh cycle.

CONCLUSIONS

This novel strategy could be appropriate for endometriosis patients who are temporarily unsuitable for fresh embryo transfer. The GnRH antagonist protocol can be combined with the whole embryo freezing strategy to achieve CCPR and CLBR similar to the ultra-long agonist regimen, thus simultaneously avoiding the long pre-treatment duration of GnRH agonists during the ultra-long agonist protocol.

GnRH-a-Induced Perimenopausal Rat Modeling and Black Cohosh Preparations' Effect on Rat's Reproductive Endocrine

BACKGROUND

Endometriosis (EMS) is an estrogen-dependent disease, which easily recurs after operation. Gonadotropin-releasing hormone agonist (GnRH-a), an estrogen-inhibiting drug, can effectively inhibit the secretion of gonadotropin by pituitary gland, so as to significantly decrease the ovarian hormone level and facilitate the atrophy of ectopic endometrium, playing a positive role in preventing postoperative recurrence. The application of GnRH-a can lead to the secondary low estrogen symptoms, namely the perimenopausal symptoms, and is a main reason for patients to give up further treatment. The add-back therapy based on sex hormones can well address the perimenopausal symptoms, but long-term use of hormones may cause the recurrence of EMS, as well as liver function damage, venous embolism, breast cancer and other risks, which has long been a heated topic in the industry. Therefore, it is necessary to find effective and safe anti-additive drugs soon. Studies at home and abroad show that, as a plant extract, isopropanolic extract of cimicifuga racemosa (ICR) can well relieve the perimenopausal symptoms caused by natural menopause. Some studies have preliminarily confirmed that black cohosh preparations can antagonize perimenopausal symptoms of EMS patients treated with GnRH-a after operation.

OBJECTIVE

To establish a rat model of perimenopausal symptoms induced by GnRH-a injection, for the purposes of laying a foundation for further research and preliminarily exploring the effect of black cohosh preparations on reproductive endocrine of the rat model.

METHOD

The rat model of perimenopausal symptoms was established by GnRH-a injection, and normal saline (NS injection) was used as the control. The rats were randomly divided into four groups according to different modeling methods and drug intervention schemes. GnRH-a injection + normal saline intervention group (GnRH-a + NS), normal saline injection control + normal saline intervention group (NS + NS), GnRH-a injection + estradiol intervention group (GnRH-a + E2), and GnRH-a injection + black cohosh preparations intervention group (GnRH-a + ICR). After modelling was assessed to be successful with the vaginal smear method, the corresponding drugs were given for intervention for 28d. In the process of rat modeling and drug intervention, the skin temperature and anus temperature of the rat tails were measured every other day, the body weights of the rats were measured every other day, and the dosage was adjusted according to the body weight. After the intervention was over, the serum sex hormone level, the uterine weight, the uterine index, and the endometrial histomorphology changes, as well as the ovarian weight, the ovarian index, and the morphological changes of ovarian tissues of each group were measured.

RESULTS

(1) The vaginal cell smears of the control group (NS + NS) showed estrous cycle changes, while other model rats had no estrous cycle of vaginal cells. (2) The body weight gains of the GnRH-a + NS, GnRH-a + E2 and GnRH-a + ICR groups were significantly higher than that of the NS + NS control group. The intervention with E2 and ICR could delay the weight gain trend of rats induced by GnRH-A. (3) After GnRH-a injection, the temperature of the tail and anus of rats showed an overall upward trend, and the intervention with E2 and ICR could effectively improve such temperature change. (4) The E2, FSH, and LH levels in the GnRH-a + NS, GnRH-a + E2, and GnRH-a + ICR groups were significantly lower than those in the NS + NS group (P < 0.01). The E2 level was significantly higher and the LH level was significantly lower in the GnRH-a + E2 group than those in the GnRH-a + NS and GnRH-a + ICR groups (P < 0.05). Compared with those of the GnRH-a + NS and GnRH-a + ICR groups, the FSH level of the GnRH-a + E2 group showed a slight downward trend, but the difference was not statistically significant (P > 0.05). There was no significant difference in the levels of sex hormones between the GnRH-a + NS group and GnRH-a + ICR group (P > 0.05). (5) Compared with those of the NS + NS group, the uterine weight and uterine index of the GnRH-a + NS, GnRH-a + E2 and GnRH-a + ICR groups significantly decreased (P < 0.01). In a comparison between the groups, the uterine weight and uterine index in the GnRH-a + NS and GnRH-a + ICR groups were significantly lower than those in the GnRH-a + E2 group (P < 0.01). There was a statistical difference in the uterine weight and uterine index between the GnRH-a + NS group and GnRH-a + ICR group (P > 0.05). (6) Compared with those of the NS + NS group, the ovarian weight and ovarian index of the GnRH-a + NS, GnRH-a + E2 and GnRH-a + ICR groups significantly decreased (P < 0.01). There was no statistical difference in the ovarian weight and ovarian index among the GnRH-a + E2, GnRH-a + NS and GnRH-a + ICR groups (P > 0.05). (7) Compared with those in the NS + NS group, the number of primordial follicles increased significantly, while the number of growing follicles and mature follicles decreased significantly in the GnRH-a + NS, GnRH-a + E2, and GnRH-a + ICR groups (P < 0.01), but there was a statistical difference in the total number of follicles among the four groups (P > 0.05).

CONCLUSIONS

The GnRH-a injection could achieve the desired effect. The animal model successfully achieved a significant decrease in the E2, FSH, and LH levels in rats, and could cause the rats to have rising body surface temperature similar to hot flashes in the perimenopausal period. The intervention with E2 and ICR could effectively relieve such "perimenopausal symptoms", and ICR had no obvious effect on the serum sex hormone level in rats.

Gonadotropin-releasing hormone analogs: Mechanisms of action and clinical applications in female reproduction

Extra-hypothalamic GnRH and extra-pituitary GnRH receptors exist in multiple human reproductive tissues, including the ovary, endometrium and myometrium. Recently, new analogs (agonists and antagonists) and modes of GnRH have been developed for clinical application during controlled ovarian hyperstimulation for assisted reproductive technology (ART). Additionally, the analogs and upstream regulators of GnRH suppress gonadotropin secretion and regulate the functions of the reproductive axis. GnRH signaling is primarily involved in the direct control of female reproduction. The cellular mechanisms and action of the GnRH/GnRH receptor system have been clinically applied for the treatment of reproductive disorders and have widely been introduced in ART. New GnRH analogs, such as long-acting GnRH analogs and oral nonpeptide GnRH antagonists, are being continuously developed for clinical application. The identification of the upstream regulators of GnRH, such as kisspeptin and neurokinin B, provides promising potential to develop these upstream regulator-related analogs to control the hypothalamus-pituitary-ovarian axis.

The effectiveness of different down-regulating protocols on in vitro fertilization-embryo transfer in endometriosis: a meta-analysis

BACKGROUND

To investigate the effectiveness of the GnRH-a ultra-long protocol, GnRH-a long protocol, and GnRH-a short protocol used in in vitro fertilization-embryo transfer (IVF-ET) in infertile women with endometriosis.

METHODS

We searched PubMed, Embase, Web of Science, Cochrane Library, Elsevier Science Direct, OA Library, Google Scholar, China National Knowledge Infrastructure (CNKI), Wanfang Data Knowledge Service Platform, China Science and Technology Journal database, and the China Biology Medicine disc for randomized controlled trials (RCTs) and observational studies (non-RCTs) to evaluate the efficacy of the GnRH-a ultra-long protocol, GnRH-a long protocol, and GnRH-a short protocol in IVF-ET in infertile patients with endometriosis.

RESULTS

A total of 21 studies in compliance with the standard literature were included, and RCT and non-RCT studies were analyzed separately. This meta-analysis showed that the GnRH-a ultra-long protocol could improve the clinical pregnancy rate of infertile patients in RCT studies, especially in patients with stages III-IV endometriosis (RR = 2.04, 95% CI: 1.37~3.04, P < 0.05). However, subgroup analysis found the different down-regulation protocols provided no significant difference in improving clinical outcomes in patients with endometriosis in the non-RCT studies.

CONCLUSION

This study suggests that the GnRH-a ultra-long protocol can improve the clinical pregnancy rate of the patients with stages III-IV endometriosis in RCT studies. Although it is generally believed that the results of RCT are more reliable, the conclusions of the non-RCT studies cannot be easily neglect, which let us draw conclusions more cautious.

Does the type of GnRH analogue used, affect live birth rates in women with endometriosis undergoing IVF/ICSI treatment, according to the rAFS stage?

Since the introduction of gonadotropin-releasing hormone (GnRH) antagonists, an extensive amount of literature investigating the role of the downregulation protocols on pregnancy outcomes has been published. However, these studies were mainly performed in the general infertile population where patients with endometriosis were often excluded or underrepresented. This study is a large retrospective cohort study including 386 endometriosis patients undergoing IVF/ICSI, who had been previously classified according to the rAFS system. Patients were stimulated either a long GnRH agonist or GnRH antagonist protocol. Depending on endometriosis stage, patients were divided into two groups: endometriosis stage I-II and endometriosis stage III-IV. Each group was subdivided, based on the type GnRH analog used. When comparing the GnRH agonist and antagonist groups, patients with endometriosis stage I-II, had a tendency toward higher β-hCG positive, clinical pregnancy, and live birth rates (42.8% vs. 26.7%; p = .07) in favor of GnRH agonist use. In endometriosis stage III-IV, no differences were observed between agonist and antagonist cycle in any of the pregnancy outcomes. Multivariate regression analysis did not reveal any significant predictor of live birth after adjusting for relevant confounders. Based on our findings, the chance to have a liveborn in endometriosis population seems not to be affected by the type of GnRH analog used, at least in advanced stages. Findings from stage I-II endometriosis cases merit consideration and further evaluation in a larger sample size is warranted.

The role of the B lymphocytes in endometriosis: A systematic review

The physiopathology of endometriosis is not completely understood and its progression is associated with a local and systemic inflammatory reaction. It is important to clarify the potential role of the immune system to better understand its implication in the pathogenesis of endometriosis, which includes the study of the role of B cells and antibodies. The aim of this study was to review the literature about the role of B lymphocytes in endometriosis. A search for "endometriosis", "B cells" and "B lymphocytes" in databases resulted in 140 citations; after applying inclusion and exclusion criteria, a total of 22 studies were assessed. The analyzed samples in the studies varied and different markers and techniques were used by the authors to evaluate the direct or indirect role of B lymphocytes in endometriosis. Most studies demonstrated increased number and/or activation of B cells while seven studies found no difference and two studies showed decreased number of B cells. Increased B lymphocytes and excessive production of autoantibodies in endometriosis have been described in the literature, but their role in the development of the disease is not well understood. Moreover, the association of these factors with clinical symptoms, location and severity of the disease has not been investigated. Further studies are necessary to clarify the role of B cells in the development of endometriosis and propose new therapeutic strategies such as the use of drugs that target these cells.

GnRH agonist administration prior to embryo transfer in freeze-all cycles of patients with endometriosis or aberrant endometrial integrin expression

Prolonged gonadotrophin-releasing hormone agonist (GnRHa) administration before IVF with fresh embryo transfer to patients with endometriosis or aberrant endometrial integrin expression (-integrin) improves outcomes but may suppress ovarian response and prevents elective cryopreservation of all embryos. This retrospective cohort pilot study evaluates freeze-all cycles with subsequent prolonged GnRHa before embryo transfer in these populations. Patients from 2010 to 2015 who met inclusion criteria and received a long-acting GnRHa every 28 days twice before FET were evaluated. A subset underwent comprehensive chromosomal screening (CCS) after trophectoderm biopsy. Three groups were identified: Group 1: + CCS, +endometriosis (20 patients, 20 transfers); Group 2: +CCS, -integrin (12 patients, 13 transfers); Group 3: no CCS, +endometriosis or -integrin (10 patients, 12 transfers); Group 4: all transfers after CCS for descriptive comparison only (n = 2809). Baseline characteristics were similar among Groups 1-3 except that the mean surgery to oocyte aspiration interval was longer for Group 1 than Group 3. Implantation and ongoing pregnancy rates were statistically similar among the three groups and compared favourably to Group 4. A non-significant trend towards improved outcomes was noted in Group 1. Prolonged GnRHa after freeze-all in these patients avoids excessive ovarian suppression and results in excellent outcomes.

Dienogest treatment after ovarian endometrioma removal in infertile women prior to IVF

BACKGROUND

Severe forms of genital endometriosis are known to be associated with infertility and its subsequent treatment failure. Both gonadotropin-releasing hormone analogs (a-GnRH) and dienogest have been suggested as additional hormone therapy for patients with endometriomas. However, the result of hormonal suppression before an in vitro fertilization (IVF) cycle remains undetermined.

MATERIALS AND METHODS

A prospective cohort study of 144 infertile women planning IVF after laparoscopic surgery of ovarian endometriomas was conducted at our department in 2012-2015. Patients were divided into three groups: group I (N = 38) with dienogest course, group II (N = 70) with a-GnRH group III (N = 70) without any hormonal therapy within 6 months preceding IVF.

RESULTS

The study groups did not differ by removed endometriomas size and ovarian reserve indicators. The gonadotropin dose per Cycle was higher, while the number of retrieved oocytes was lower in group III patients (p < .001). In women with dienogest pretreatment, clinical pregnancy rate was 2.5 times (44.7% versus 16.7%, p = .012) and delivery rate - three times higher (36.8% versus 11.1%, p = .013) as compared with those from group III.

CONCLUSIONS

The present study confirms the necessity of pre-cycle medical interventions in women with ovarian forms of endometriosis undergoing IVF. We suggest dienogest to be possibly more efficient treatment option for this kind of patients.

Involvement of NADPH oxidase and NF-κB activation in CXCL1 induction by vascular endothelial growth factor in human endometrial epithelial cells of patients with adenomyosis

Chemokines were known to participate in inflammation and angiogenesis but have been recently recognized to be involved in embryonic implantation and endometrium-related pathologies. Among these chemokines, the CXC chemokines, such as CXCL1, have potential roles to work as biomarkers to identify patients with uterine adenomyosis. In this study, human endometrial epithelial cells (HEECs) were derived from patients' endometrium with adenomyosis. The inductive effects of CXCL1 production by various mediators/growth factors were investigated in the HEECs. Of the tested mediators, VEGF was found to be the most effective. The immunohistochemistry and RT-PCR analysis revealed a positive staining for VEGF and CXCL1 at the epithelium and the presence of CXCL1 in the human endometrium specimens, respectively. The CXCL1 induction by VEGF could be reduced by the antagonist for VEGF receptor (VEGFR), and by the inhibitors for NADPH oxidase and NF-κB signaling pathway. However, it was not affected by sex hormones and the inhibitors for MAPKs, PI-3K, protein kinase A and C. In parallel, VEGF induced p47 phox NADPH oxidase activation, IκBα phosphorylation, NF-κB translocation and NF-κB-DNA complex formation in the HEECs. Moreover, the CXCL1 released by the HEECs with VEGF stimulation attracted vascular endothelial cell migration. Taken together, we show that VEGF and CXCL1 are expressed in epithelium of the endometrium with adenomyosis and demonstrate here for the first time that VEGF is capable of inducing CXCL1 expression in HEECs through VEGFR, p47 phox NADPH oxidase and NF-κB signaling pathway, which is functionally required for attracting vascular endothelial cell migration.

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.

Analogs of Luteinizing Hormone-Releasing Hormone in the Treatment of Endometriosis

Agonists of luteinizing hormone-releasing hormone (LHRH) induce a reversible hypoestrogenic state through the down-regulation of LHRH receptors and desensitization of the pituitary. Since endometrial implants are estrogen sensitive, LHRH agonists have frequently been used for medical treatment of endometriosis. Nowadays, LHRH agonists can be considered in general as a second-line medical treatment for endometriosis-related symptoms, as oral therapy with dienogest is as effective and has fewer side effects. However, therapy with LHRH agonists for 3-6 months prior to in vitro fertilization remains the treatment of choice in patients with endometriosis, as it significantly increases pregnancy rates.

LHRH agonists are used prior to surgery and as an adjuvant after an operation to prevent recurrence or prolong disease-free intervals. Adverse effects of LHRH agonists are due to hypoestrogenism and include hot flushes, vaginal dryness, loss of libido, sleep disturbances and a diminished bone density which limits the duration of their administration to 6 months. For long-term treatment, add-back of estrogen and/or progestin,/or progestin only with or without bisphosphonates, can be used, but existing studies only cover a 12-month period of treatment.

LHRH antagonists competitively block the pituitary receptors for LHRH. Consequently, a partial pharmacological hypophysectomy with a reduction of the estrogen levels to a desired level is possible if LHRH antagonists are adequately dosed. As endometriotic implants require relatively high levels of estrogen, partially lower plasma levels of estrogens are sufficient to prevent the loss of bone density. A long-term treatment without add-back therapy is also possible.

Endometriosis-Related Infertility: The Role of the Assisted Reproductive Technologies

The assisted reproductive technologies, particularly in vitro fertilization (IVF), represent the most efficient and successful means of overcoming infertility associated with endometriosis. Although older studies suggest that IVF outcomes are compromised in endometriosis patients, more contemporary reports show no differences compared to controls. The exception may be evidence of poorer outcomes and diminished ovarian response in women with advanced disease, particularly those with significant ovarian involvement or prior ovarian surgery. Prolonged pre-IVF cycle suppressive medical therapy, particularly gonadotropin releasing hormone agonists, appears to improve success rates in a subset of endometriosis patients. However, as of yet, there is no diagnostic marker to specifically identify those who would most benefit from this approach. Pre-IVF cycle surgical resection of nonovarian disease has not been consistently shown to improve outcomes with the possible exception of resection of deeply invasive disease, although the data is limited. Precycle resection of ovarian endometriomas does not have benefit and should only be performed for gynecologic indications. Indeed, there is a large body of evidence to suggest that this procedure may have a deleterious impact on ovarian reserve and response. A dearth of appropriately designed trials makes development of definitive treatment paradigms challenging.

A novel angiogenesis inhibitor bevacizumab induces apoptosis in the rat endometriosis model

Our aim was to investigate the effects of anti-vascular endothelial growth factor (anti-VEGF) antibody Bevacizumab on endometrial explants and on apoptotic gene expression levels in the rat endometriosis model. Endometriotic implants were surgically formed, and rats treated with (i) 1 mg/kg single subcutaneous injection of depot leuprolide acetate; (ii) 2.5 mg/kg of single intaperitoneal injection of bevacizumab; (iii) intraperitoneal injection of saline. Histopathologic scores and adhesion scores of endometriotic foci and levels of Bcl-2-associated X protein (Bax), Cytochrome c (Cyt-c), B-cell lymphoma/leukemia 2 (Bcl-2) and B-cell lymphoma-extra large (Bcl-xl) mRNA gene expressions of endometriotic foci. Bevacizumab treatment decreased the endometriotic explant size compared with control. Bevacizumab-treated rats had lower total adhesion scores when compared with the control group. Semi-quantitative evaluation of the persistence of endometrial epithelial cells in the explants showed a lower score in gonadotropin-releasing hormone (GnRH) agonist-treated rats compared with control rats. In Bevacizumab increased expression of Bax 3.1-fold, Cyt-c 1.3-fold and decreased expression of Bcl-2 0.4-fold, Bcl-xl 0.8-fold compared with the control group. The GnRH agonist increased expression of Bax 3.0 fold, Cyt-c 1.3 fold and decreased expression of Bcl-2 0.4-fold, Bcl-xl 0.8-fold, compared with the control group. This study suggests that a novel angiogenesis inhibitor, anti-VEGF antibody bevacizumab is as effective as GnRH agonist in the regression of the endometriotic lesions in rat endometriosis model. One possible mechanism of this effect is the induction of apoptosis.

GnRH agonists induce endometrial epithelial cell apoptosis via GRP78 down-regulation

Background

Endometriosis is a benign chronic gynecological disease that affects women of reproductive age, characterized by the presence of functional endometrial tissues outside the uterine cavity. GnRH agonists exhibit anti-proliferative and apoptosis-enhancing activities and have long been used for the treatment of endometriosis. There is a critical need to identify the signaling modules involving GnRH agonist therapy for the treatment of endometriosis. In this study, we compared the proteomic profiles of endometriosis in patients before and after GnRH agonist therapy to identify proteins that might provide further information concerning the mechanisms underlying the functions of GnRH agonists.

Methods

A total of 55 protein spots with different abundances were observed using Difference Gel Electrophoresis (DIGE), and 26 of these proteins were assigned clear identities through Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Tandem Mass Spectroscopy (MALDI-TOF/TOF MS).

Results

We validated four of these proteins through Western blotting and immunohistochemistry using human endometrial tissue. We also characterized the effect of Leuprolide acetate (LA) on the apoptosis of eutopic endometrial epithelial cells. LA treatment significantly promoted the apoptosis of eutopic endometrial epithelial cells and inhibited the expression of the anti-apoptotic factor GRP78. GRP78 knockdown enhanced LA-induced cell apoptosis, whereas, the overexpression of GRP78 in eutopic endometrial epithelial cells suppresses LA-induced apoptosis.

Conclusion

These results suggest that GnRH agonists induce endometrial epithelial cell apoptosis via GRP78 down-regulation. This study might provide an important molecular framework for further evaluation of GnRH agonist therapy.

ART and uterine pathology: how relevant is the maternal side for implantation?

BACKGROUND

Assisted reproduction technology (ART) has become a standard treatment for infertile couples. Increased success rates obtained over the years have resulted primarily from improved embryo quality, but implantation rates still remain lower than expected. The uterus, an important player in implantation, has been frequently neglected. While a number of uterine pathologies have been associated with decreased natural fertility, less information exists regarding the impact of these pathologies in ART. This report reviews the evidence to help clinicians advise ART patients.

METHODS

An electronic search of PubMed and EMBASE was performed to identify articles in the English, French or Spanish language published until May 2014 which addressed uterine pathology and ART. Data from natural conception were used only in the absence of data from ART. Studies were classified in decreasing categories: RCTs, prospective controlled trials, prospective non-controlled trials, retrospective studies and experimental studies. Studies included in lower categories were only used if insufficient evidence was available. Pooled data were obtained from systematic reviews with meta-analyses when available. The summary of the evidence for the different outcomes and the degree of the recommendation for interventions were based on the GRADE (Grading of Recommendations Assessment, Development and Evaluation) statement recommendations.

RESULTS

There is strong evidence that surrogacy is effective for uterine agenesia. For the remaining pathologies, however, there is very little evidence that the established treatments improve outcomes, or that these pathologies have a negative effect on ART. In the presence of an apparently normal uterus, assessing endometrial receptivity (ER) is the goal; however diagnostic tests are still under development.

CONCLUSIONS

The real effect of different uterine/endometrial integrity pathologies on ART is not known. Moreover, currently proposed treatments are not based on solid evidence, and little can be done to assess ER in normal or abnormal conditions. No strong recommendations can be given based on the published experience, bringing an urgent need for well-designed studies. In this context, we propose algorithms to study the uterus in ART.

Gonadotropin-releasing hormone-regulated prohibitin mediates apoptosis of the gonadotrope cells

GnRH regulates circulating levels of the gonadotropins but has also been implicated in establishing the gonadotrope cell population. Consistent with this, GnRH induces proliferation of partially differentiated gonadotropes, while reducing the numbers of fully differentiated cells. We have previously reported that the proapoptotic protein, prohibitin (PHB) is expressed more abundantly in gonadotrope-derived LβT2 cells than in partially differentiated αT3-1 gonadotrope precursor cells, suggesting a possible role for PHB in GnRH-induced apoptosis. We show here that PHB is required for GnRH-induced apoptosis in mature gonadotropes. PHB expression and activity are regulated by GnRH: its transcription is via c-Jun NH2-terminal kinase, whereas its nuclear export follows activation of ERK. Moreover, PHB levels are down-regulated by microRNA27, which is expressed at lower levels in mature gonadotropes, possibly explaining the switch to an apoptotic response with development. PHB is required for mitochondrial import of the proapoptotic BAX, whose expression is also induced by GnRH-activated c-Jun NH2-terminal kinase, as is expression of the BH3-only protein, HRK, and this too plays a role in GnRH-induced apoptosis. Finally, we show that gonadotrope-specific PHB-knockout mice display reproductive abnormalities, including a larger gonadotrope population, increased LH levels, reduced fertility, and altered gonad development. We thus demonstrate a role for PHB in GnRH-induced cell death in mature gonadotropes, which is crucial for the normal development and function of the reproductive axis.

Gonadotrophin-releasing hormone analogues and endometriosis: current strategies and new insights

BACKGROUND

Endometriosis is an estrogen-dependent chronic inflammatory disease affecting 5% to 10% of women in reproductive age and has been reported also in adolescents. Its main clinical presentations are chronic pelvic pain and infertility.

OBJECTIVE

To provide a comprehensive review of the recently published data concerning the mechanism of action of gonadotrophin-releasing hormone analogues (GnRHas) as well as to analyze their role in the management of endometriosis-associated pain and infertility in addition to its value in adolescent cases. Furthermore, to provide practical recommendations and new insights based on the best available information.

METHODS

Systematic search was performed of the Cochrane Library and Medical Literature Analysis and Retrieval System Online database looking for the different trials, reviews and various guidelines relating to GnRHas usage in the management of endometriosis-associated pain, infertility and in adolescent cases.

RESULTS

From a pathophysiological perspective, there is a growing scientific evidence that GnRHas exert its therapeutic effects by their classical pituitary downregulation and via a direct effect on the endometrial cells themselves. Accordingly, they represent an important medical option for the management of different aspects of this enigmatic disease.

CONCLUSION

GnRHas have a valuable strategic role in treatment of endometriosis-associated pain and infertility as well as in adolescents above 16 years.

GnRH agonist (buserelin)-induced in vitro apoptosis in bovine endometrium

Singh, R., Pretheeban, T. and Rajamahendran, R. 2011. GnRH agonist (buserelin)-induced in vitro apoptosis in bovine endometrium. Can. J. Anim. Sci. 91: 265–273. Apoptosis is a vital physiological process. The local modulatory role of the GnRH, GnRH-R system in uterine physiology is not clear. We investigated GnRH agonist (buserelin)-induced apoptosis in bovine endometrium. Reproductive tracts were collected from a local abattoir. The endometrial explants were sliced into smaller pieces, cultured for 20 h and then treated (6 h) with buserelin (0, 200, 500, 1000 ng mL−1), the GnRH antagonist-antide (500 ng mL−1) and antide+buserelin (500+200 ng mL−1), and stored at −80°C for RNA extraction. Two micrograms of total RNA was subjected to reverse transcription-polymerase chain reaction using gene-specific primers. Subsequently, endometrial epithelial cells were isolated from the follicular and luteal phase uteri, cultured for 48 h, characterized and treated with buserelin (200 ng mL−1), antide (500 ng mL−1), and antide+buserelin (500+200 ng mL−1) for 6 h. The cells were stained with acridine orange-ethidium bromide and visualized and counted under a fluorescent microscope. Buserelin up-regulated BAX (200 ng mL−1) and CASPASE3 mRNA (200 and 500 ng mL−1) and induced apoptosis (200 ng mL−1) at the cellular level in the follicular phase endometrium. GnRH appears to regulate uterine homeostasis in bovine endometrium at the transcriptional and cellular levels.

Aberrant expression of apoptosis-related molecules in endometriosis: a possible mechanism underlying the pathogenesis of endometriosis

Endometriosis, a disease affecting 3% to 10% of women of reproductive age, is characterized by the ectopic growth of endometrial tissue under the influence of estrogen. It is also becoming recognized as a condition in which ectopic endometrial cells exhibit abnormal proliferative and apoptotic regulation in response to appropriate stimuli. Apoptosis plays a critical role in maintaining tissue homeostasis and represents a normal function to eliminate excess or dysfunctional cells. Accumulated evidence suggests that, in healthy women, endometrial cells expelled during menstruation do not survive in ectopic locations because of programmed cell death, while decreased apoptosis may lead to the ectopic survival and implantation of these cells, resulting in the development of endometriosis. Both the inability of endometrial cells to transmit a "death" signal and the ability of endometrial cells to avoid cell death have been associated with increased expression of antiapoptotic factors and decreased expression of preapoptotic factors. Further investigations may elucidate the role of apoptosis-associated molecules in the pathogenesis of endometriosis. Medical treatment with apoptosis-inducing agents may be novel and promising therapeutic strategy for endometriosis.

Gonadotropin-releasing hormone agonist and add-back therapy: what do the data show?

PURPOSE OF REVIEW

Endometriosis is a gynecologic disorder that can lead to debilitating chronic pelvic pain and infertility. Gonadotropin-releasing hormone agonists (GnRHa) have emerged as a primary medical therapy for patients with symptomatic disease, but secondary hypoestrogenic side effects may limit compliance. Add-back therapy is a means of surmounting this problem.

RECENT FINDINGS

Progestins such as norethindrone acetate may be administered with or without addition of low doses of estrogens to safely and effectively extend GnRHa therapy while minimizing side effects. Recent studies have demonstrated that the use of add-back enhances compliance and duration of therapy. The initiation of an add-back should not be deferred given evidence demonstrating an increase in vasomotor symptoms and bone loss if not administered concomitantly. The subset of adolescents with endometriosis who require GnRHa therapy should be administered an add-back, but require careful monitoring of bone mineral density.

SUMMARY

Implementation of an appropriately selected add-back will significantly reduce hypoestrogenic side effects, enhance compliance, and allow for prolongation of therapy without interfering with the efficacy of GnRHa in treating symptomatic endometriosis.

Effects of the levonorgestrel-releasing intrauterine system on cell proliferation, Fas expression and steroid receptors in endometriosis lesions and normal endometrium

BACKGROUND

The objectives of this study were: (i) to evaluate the effects of the levonorgestrel-releasing intrauterine system (LNG-IUS) on both proliferation and apoptosis markers and hormone receptors of the eutopic and ectopic endometrium of women experiencing pain related to endometriosis and (ii) to compare the results with those obtained with GnRH agonist (GnRHa) injections.

METHODS

Pre- and post-treatment endometrium and endometriosis specimens were obtained from 22 women experiencing pain related to endometriosis who were treated with LNG-IUS (n = 11) or GnRHa (n = 11) for 6 months. Changes in the expression of proliferating cell nuclear antigen, Fas, progesterone receptor (PRA) and estrogen receptor alpha (ER-alpha) were analyzed by immunohistochemistry.

RESULTS

The cell proliferation index was significantly reduced in the epithelium and stroma of both the eutopic and the ectopic endometrium after treatment with the LNG-IUS and GnRHa. Only LNG-IUS users showed an increased H-score for Fas in the epithelium of the eutopic and ectopic endometrium (P < 0.05). Expression of ER-alpha and PRA by the glandular epithelium was lower in the eutopic endometrium after both treatments, but this reduction was noted in the ectopic endometrium only after LNG-IUS treatments (P < 0.05). No difference was detected between groups for any of the markers.

CONCLUSIONS

LNG-IUS reduced both cell proliferation and the expression of PRA and ER-alpha and increased Fas expression in the eutopic and ectopic endometrium of patients with endometriosis. Some of these actions were not observed with GnRHa.

Comparison of the effects of cetrorelix, a GnRH antagonist, and leuprolide, a GnRH agonist, on experimental endometriosis

AIM

In the present study, we aimed to compare the effects of cetrorelix and leuprolide on endometriosis.

METHODS

This randomized, placebo-controlled, single-blind, experimental study was performed on 45 Wistar adult female rats in the Experimental Surgery Laboratory at Ondokuz Mayis University. After the peritoneal implantation of endometrial tissue, rats were randomized to three equal intervention groups: (i) control group, (ii) leuprolide group, and (iii) cetrorelix group. Six weeks later, following implant volume measurements (volume-1) by performing a second laparotomy, saline (0.1 cc/rat) was administered subcutaneously to the control group once a week, leuprolide (0.075 mg/kg) subcutaneously to the leuprolide group twice at 4-week intervals and cetrorelix (0.001 mg/rat/day) subcutaneously to the cetrorelix group for 8 weeks. At the end of the treatment, by performing a third laparotomy, implant volumes were remeasured (volume-2) and implants were totally excised for histopathological examination. The volume-1 and volume-2 values within the groups, and stromal and glandular tissue scores between the groups were compared.

RESULTS

In both the leuprolide group and the cetrorelix group, volume-2 as compared to volume-1 had significantly reduced (P < 0.01, P < 0.01 respectively), while there was no significant volume change in the control group (P > 0.05). In this group, when compared with the control group, glandular and stromal tissues had significantly lessened (P < 0.01, P < 0.01 respectively).

CONCLUSION

Leuprolide and cetrorelix were found to have similar efficacy in the regression of both the size and the histological structure of experimental endometriotic implants.

GnRH signaling in intrauterine tissues

Type I GnRH (GnRH-I, GNRH1) and type II GnRH (GnRH-II, GNRH2), each encoded by separate genes, have been identified in humans. The tissue distribution and functional regulation of GnRH-I and GnRH-II clearly differ despite their comparable cDNA and genomic structures. These hormones exert their effects by binding to cell surface transmembrane G protein coupled receptors and stimulating the Gq/11 subfamily of G proteins. The hypothalamus and pituitary are the main origin and target sites of GnRH, but numerous studies have demonstrated that extra-hypothalamic GnRH and extra-pituitary GnRH receptors exist in different reproductive tissues such as the ovary, endometrium, placenta, and endometrial cancer cells. In addition to endocrine regulation, GnRH is also known to act in an autocrine and paracrine manner to suppress cell proliferation and activate apoptosis in the endometrium and endometrial cancer cells through several mechanisms. Both GnRH-I and GnRH-II exhibit regulatory roles in tissue remodelling during embryo implantation and placentation, which suggests that these hormones may have important roles in embryo implantation and early pregnancy. The presence of varied GnRH and GnRH receptor systems demonstrate their different roles in distinct tissues using dissimilar mechanisms. These may result in the generation of new GnRH analogues used for several hormone-related diseases.