Prostaglandin synthesis in the endometrium of women with ovular dysfunctional uterine bleeding

Prostaglandin E2 regulates the plasminogen activator pathway in human endometrial endothelial cells: a new in vitro model to investigate heavy menstrual bleeding

OBJECTIVE

To study the role of PGE2 in regulating plasminogen activator inhibitor-1 (PAI-1) and tissue plasminogen activator (tPA) in human primary endometrial endothelial cells (HEECs) from women with normal menstrual bleeding (NMB) and heavy menstrual bleeding (HMB).

DESIGN

In vitro study using endometrial endothelial cells.

SETTING

Research laboratory setting.

PATIENTS

Women with NMB and HMB provided endometrial biopsy samples.

INTERVENTIONS

Prostaglandin E2 and PGE2 receptor-selective agonists were administered to cultured HEECs.

MAIN OUTCOME MEASURES

Levels of PAI-1 and tPA in NMB-HEECs and HMB-HEECs after treatment with PGE2 and receptor-selective agonists.

RESULTS

Prostaglandin E2 increased total PAI-1 levels in NMB-HEECs, but not in HMB-HEECs, which had higher baseline PAI-1 levels. PGE2 receptors (PTGER)1 and PTGER2 agonists increased PAI-1 in NMB-HEECs, whereas PTGER3 and PTGER4 did not. Prostaglandin E2 had no effect on tPA levels in either NMB-HEECs or HMB-HEECs.

CONCLUSIONS

Prostaglandin E2, through PTGER1 and PTGER2, regulates the plasminogen activator system in NMB-HEECs, suggesting a role in reducing fibrinolytic activity during normal menstrual cycles. The lack of PGE2 effect and elevated baseline PAI-1 in HMB-HEECs support using this in vitro model to further understand prostaglandin pathways in NMB and HMB.

COVID-19 and abnormal uterine bleeding: potential associations and mechanisms

The impact of COVID-19 on menstruation has received a high level of public and media interest. Despite this, uncertainty exists about the advice that women and people who menstruate should receive in relation to the expected impact of SARS-CoV-2 infection, long COVID or COVID-19 vaccination on menstruation. Furthermore, the mechanisms leading to these reported menstrual changes are poorly understood. This review evaluates the published literature on COVID-19 and its impact on menstrual bleeding, discussing the strengths and limitations of these studies. We present evidence consistent with SARS-CoV-2 infection and long COVID having an association with changes in menstrual bleeding parameters and that the impact of COVID vaccination on menstruation appears less significant. An overview of menstrual physiology and known causes of abnormal uterine bleeding (AUB) is provided before discussing potential mechanisms which may underpin the menstrual disturbance reported with COVID-19, highlighting areas for future scientific study. Finally, consideration is given to the effect that menstruation may have on COVID-19, including the impact of the ovarian sex hormones on acute COVID-19 severity and susceptibility and reported variation in long COVID symptoms across the menstrual cycle. Understanding the current evidence and addressing gaps in our knowledge in this area are essential to inform public health policy, direct the treatment of menstrual disturbance and facilitate development of new therapies, which may reduce the severity of COVID-19 and improve quality of life for those experiencing long COVID.

Angiogenesis in abnormal uterine bleeding: a narrative review

BACKGROUND

Abnormal uterine bleeding (AUB) has a significant socioeconomic impact since it considerably impacts quality of life. Therapeutic options are frequently based on trial and error and do not target disease aetiology. Pathophysiological insight in this disease is required for the development of novel treatment options. If no underlying cause is found for the AUB (e.g. fibroids, adenomyosis, polyps), endometrial-AUB (AUB-E) is usually caused by a primary endometrium disorder. When AUB is induced by prescribed (exogenous) hormones, it is classified as iatrogenic-AUB (AUB-I). Considering vascular modulation and function, AUB-E and AUB-I both could potentially result from abnormal vascularization in the endometrium due to alterations in the process of angiogenesis and vascular maturation.

OBJECTIVE AND RATIONALE

We aim to investigate the fundamental role of angiogenesis and vascular maturation in patients with AUB and hypothesize that aberrant endometrial angiogenesis has an important role in the aetiology of both AUB-E and AUB-I, possibly through different mechanisms.

SEARCH METHODS

A systematic literature search was performed until September 2021 in the Cochrane Library Databases, Embase, PubMed, and Web of Science, with search terms such as angiogenesis and abnormal uterine bleeding. Included studies reported on angiogenesis in the endometrium of premenopausal women with AUB-E or AUB-I. Case reports, letters, reviews, editorial articles, and studies on AUB with causes classified by the International Federation of Gynecology and Obstetrics as myometrial, oncological, or infectious, were excluded. Study quality was assessed by risk of bias, using the Cochrane tool and the Newcastle-Ottawa Scale.

OUTCOMES

Thirty-five out of 2158 articles were included. In patients with AUB-E, vascular endothelial growth factor A and its receptors (1 and 2), as well as the angiopoietin-1:angiopoietin-2 ratio and Tie-1, were significantly increased. Several studies reported on the differential expression of other pro- and antiangiogenic factors in patients with AUB-E, suggesting aberrant vascular maturation and impaired vessel integrity. Overall, endometrial microvessel density (MVD) was comparable in patients with AUB-E and controls. Interestingly, patients with AUB-I showed a higher MVD and higher expression of proangiogenic factors when compared to controls, in particular after short-term hormone exposure. This effect was gradually lost after longer-term exposure, while alterations in vessel maturation were observed after both short- and long-term exposures.

WIDER IMPLICATIONS

AUB-E and AUB-I are most likely associated with aberrant endometrial angiogenesis and impaired vessel maturation. This review supports existing evidence that increased proangiogenic and decreased antiangiogenic factors cause impaired vessel maturation, resulting in more fragile and permeable vessels. This matches our hypothesis and these mechanisms appear to play an important role in the pathophysiology of AUB-E and AUB-I. Exploring the alterations in angiogenesis in these patients could provide treatment targets for AUB.

From menarche to menopause, heavy menstrual bleeding is the underrated compass in reproductive health

Menstruation is defined as monthly uterine bleeding, regarded as a sign of reproductive health. When characterized by excessive bleeding (heavy menstrual bleeding [HMB]), it may act as a useful clinical marker for diagnosis of reproductive diseases. Endometrial and myometrial mechanisms underlying abnormal uterine bleeding (AUB), which includes HMB, have hormonal, cellular, and molecular aspects. Structural and nonstructural causes of AUB, presenting with HMB as the major symptom, result in iron depletion and consequent anemia. Heavy menstrual bleeding can be considered as a single entity to identify the possible underlying causes, which may be different to some extent to those of AUB, as a whole. Furthermore, the difficulties in defining HMB through objective methods do not allow the current epidemiological scenario on the prevalence of the symptom among reproductive-age women to be outlined. Moreover, the introduction of new diagnostic methods, including imaging technologies, entails a revision of the available figures on HMB in different age groups from menarche to menopause. In addition, a proper diagnostic algorithm for HMB should be implemented to adapt recommendations for clinical investigation when HMB is present.

Interventions for heavy menstrual bleeding; overview of Cochrane reviews and network meta-analysis

BACKGROUND

Heavy menstrual bleeding (HMB) is excessive menstrual blood loss that interferes with women's quality of life, regardless of the absolute amount of bleeding. It is a very common condition in women of reproductive age, affecting 2 to 5 of every 10 women. Diverse treatments, either medical (hormonal or non-hormonal) or surgical, are currently available for HMB, with different effectiveness, acceptability, costs and side effects. The best treatment will depend on the woman's age, her intention to become pregnant, the presence of other symptoms, and her personal views and preferences.

OBJECTIVES

To identify, systematically assess and summarise all evidence from studies included in Cochrane Reviews on treatment for heavy menstrual bleeding (HMB), using reviews with comparable participants and outcomes; and to present a ranking of the first- and second-line treatments for HMB.

METHODS

We searched for published Cochrane Reviews of HMB interventions in the Cochrane Database of Systematic Reviews. The primary outcomes were menstrual bleeding and satisfaction. Secondary outcomes included quality of life, adverse events and the requirement of further treatment. Two review authors independently selected the systematic reviews, extracted data and assessed quality, resolving disagreements by discussion. We assessed review quality using the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) 2 tool and evaluated the certainty of the evidence for each outcome using GRADE methods. We grouped the interventions into first- and second-line treatments, considering participant characteristics (desire for future pregnancy, failure of previous treatment, candidacy for surgery). First-line treatments included medical interventions, and second-line treatments included both the levonorgestrel-releasing intrauterine system (LNG-IUS) and surgical treatments; thus the LNG-IUS is included in both groups. We developed different networks for first- and second-line treatments. We performed network meta-analyses of all outcomes, except for quality of life, where we performed pairwise meta-analyses. We reported the mean rank, the network estimates for mean difference (MD) or odds ratio (OR), with 95% confidence intervals (CIs), and the certainty of evidence (moderate, low or very low certainty). We also analysed different endometrial ablation and resection techniques separately from the main network: transcervical endometrial resection (TCRE) with or without rollerball, other resectoscopic endometrial ablation (REA), microwave non-resectoscopic endometrial ablation (NREA), hydrothermal ablation NREA, bipolar NREA, balloon NREA and other NREA.

MAIN RESULTS

We included nine systematic reviews published in the Cochrane Library up to July 2021. We updated the reviews that were over two years old. In July 2020, we started the overview with no new reviews about the topic. The included medical interventions were: non-steroidal anti-inflammatory drugs (NSAIDs), antifibrinolytics (tranexamic acid), combined oral contraceptives (COC), combined vaginal ring (CVR), long-cycle and luteal oral progestogens, LNG-IUS, ethamsylate and danazol (included to provide indirect evidence), which were compared to placebo. Surgical interventions were: open (abdominal), minimally invasive (vaginal or laparoscopic) and unspecified (or surgeon's choice of route of) hysterectomy, REA, NREA, unspecified endometrial ablation (EA) and LNG-IUS. We grouped the interventions as follows. First-line treatments Evidence from 26 studies with 1770 participants suggests that LNG-IUS results in a large reduction of menstrual blood loss (MBL; mean rank 2.4, MD -105.71 mL/cycle, 95% CI -201.10 to -10.33; low certainty evidence); antifibrinolytics probably reduce MBL (mean rank 3.7, MD -80.32 mL/cycle, 95% CI -127.67 to -32.98; moderate certainty evidence); long-cycle progestogen reduces MBL (mean rank 4.1, MD -76.93 mL/cycle, 95% CI -153.82 to -0.05; low certainty evidence), and NSAIDs slightly reduce MBL (mean rank 6.4, MD -40.67 mL/cycle, -84.61 to 3.27; low certainty evidence; reference comparator mean rank 8.9). We are uncertain of the true effect of the remaining interventions and the sensitivity analysis for reduction of MBL, as the evidence was rated as very low certainty. We are uncertain of the true effect of any intervention (very low certainty evidence) on the perception of improvement and satisfaction. Second-line treatments Bleeding reduction is related to the type of hysterectomy (total or supracervical/subtotal), not the route, so we combined all routes of hysterectomy for bleeding outcomes. We assessed the reduction of MBL without imputed data (11 trials, 1790 participants) and with imputed data (15 trials, 2241 participants). Evidence without imputed data suggests that hysterectomy (mean rank 1.2, OR 25.71, 95% CI 1.50 to 439.96; low certainty evidence) and REA (mean rank 2.8, OR 2.70, 95% CI 1.29 to 5.66; low certainty evidence) result in a large reduction of MBL, and NREA probably results in a large reduction of MBL (mean rank 2.0, OR 3.32, 95% CI 1.53 to 7.23; moderate certainty evidence). Evidence with imputed data suggests hysterectomy results in a large reduction of MBL (mean rank 1.0, OR 14.31, 95% CI 2.99 to 68.56; low certainty evidence), and NREA probably results in a large reduction of MBL (mean rank 2.2, OR 2.87, 95% CI 1.29 to 6.05; moderate certainty evidence). We are uncertain of the true effect for REA (very low certainty evidence). We are uncertain of the effect on amenorrhoea (very low certainty evidence). Evidence from 27 trials with 4284 participants suggests that minimally invasive hysterectomy results in a large increase in satisfaction (mean rank 1.3, OR 7.96, 95% CI 3.33 to 19.03; low certainty evidence), and NREA also increases satisfaction (mean rank 3.6, OR 1.59, 95% CI 1.09 to 2.33; low certainty evidence), but we are uncertain of the true effect of the remaining interventions (very low certainty evidence).

AUTHORS' CONCLUSIONS

Evidence suggests LNG-IUS is the best first-line treatment for reducing menstrual blood loss (MBL); antifibrinolytics are probably the second best, and long-cycle progestogens are likely the third best. We cannot make conclusions about the effect of first-line treatments on perception of improvement and satisfaction, as evidence was rated as very low certainty. For second-line treatments, evidence suggests hysterectomy is the best treatment for reducing bleeding, followed by REA and NREA. We are uncertain of the effect on amenorrhoea, as evidence was rated as very low certainty. Minimally invasive hysterectomy may result in a large increase in satisfaction, and NREA also increases satisfaction, but we are uncertain of the true effect of the remaining second-line interventions, as evidence was rated as very low certainty.

The Menstrual Endometrium: From Physiology to Future Treatments

Abnormal uterine bleeding (AUB) is experienced by up to a third of women of reproductive age. It can cause anaemia and often results in decreased quality of life. A range of medical and surgical treatments are available but are associated with side effects and variable effectiveness. To improve the lives of those suffering from menstrual disorders, delineation of endometrial physiology is required. This allows an increased understanding of how this physiology may be disturbed, leading to uterine pathologies. In this way, more specific preventative and therapeutic strategies may be developed to personalise management of this common symptom. In this review, the impact of AUB globally is outlined, alongside the urgent clinical need for improved medical treatments. Current knowledge of endometrial physiology at menstruation is discussed, focusing on endocrine regulation of menstruation and local endometrial inflammation, tissue breakdown, hypoxia and endometrial repair. The contribution of the specialised endometrial vasculature and coagulation system during menstruation is highlighted. What is known regarding aberrations in endometrial physiology that result in AUB is discussed, with a focus on endometrial disorders (AUB-E) and adenomyosis (AUB-A). Gaps in existing knowledge and areas for future research are signposted throughout, with a focus on potential translational benefits for those experiencing abnormal uterine bleeding. Personalisation of treatment strategies for menstrual disorders is then examined, considering genetic, environmental and demographic characteristics of individuals to optimise their clinical management. Finally, an ideal model of future management of AUB is proposed. This would involve targeted diagnosis of specific endometrial aberrations in individuals, in the context of holistic medicine and with due consideration of personal circumstances and preferences.

Obesity is associated with heavy menstruation that may be due to delayed endometrial repair

Heavy menstrual bleeding is common and debilitating but the causes remain ill defined. Rates of obesity in women are increasing and its impact on menstrual blood loss (MBL) is unknown. Therefore, we quantified BMI and MBL in women not taking hormones and with regular menstrual cycles and revealed a positive correlation. In a mouse model of simulated menstruation, diet-induced obesity also resulted in delayed endometrial repair, a surrogate marker for MBL. BrdU staining of mouse uterine tissue revealed decreased proliferation during menstruation in the luminal epithelium of mice on a high-fat diet. Menstruation is known to initiate local endometrial inflammation and endometrial hypoxia; hence, the impact of body weight on these processes was investigated. A panel of hypoxia-regulated genes (VEGF, ADM, LDHA, SLC2A1) showed consistently higher mean values in the endometrium of women with obesity and in uteri of mice with increased weight vs normal controls, although statistical significance was not reached. The inflammatory mediators, Tnf and Il6 were significantly increased in the uterus of mice on a high-fat diet, consistent with a pro-inflammatory local endometrial environment in these mice. In conclusion, obesity was associated with increased MBL in women. Mice given a high-fat diet had delayed endometrial repair at menstruation and provided a model in which to study the influence of obesity on menstrual physiology. Our results indicate that obesity results in a more pro-inflammatory local endometrial environment at menstruation, which may delay endometrial repair and increase menstrual blood loss.

Markers of human endometrial hypoxia can be detected in vivo and ex vivo during physiological menstruation

STUDY QUESTION

Can markers of human endometrial hypoxia be detected at menstruation in vivo?

SUMMARY ANSWER

Our in vivo data support the presence of hypoxia in menstrual endometrium of women during physiological menstruation.

WHAT IS KNOWN ALREADY

Current evidence from animal models and human in vitro studies suggests endometrial hypoxia is present at menstruation and drives endometrial repair post menses. However, detection of human endometrial hypoxia in vivo remains elusive.

STUDY DESIGN, SIZE, DURATION

We performed a prospective case study of 16 women with normal menstrual bleeding.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Reproductively aged female participants with a regular menstrual cycle underwent objective measurement of their menstrual blood loss using the alkaline haematin method to confirm a loss of <80 ml per cycle. Exclusion criteria were exogenous hormone use, an intrauterine device, endometriosis or fibroids >3 cm. Participants attended for two MRI scans; during days 1-3 of menstruation and the early/mid-secretory phase of their cycle. The MRI protocol included dynamic contrast-enhanced MRI and T2* quantification. At each visit, an endometrial sample was also collected and hypoxia-regulated repair factor mRNA levels (ADM, VEGFA, CXCR4) were quantified by RT-qPCR.

MAIN RESULTS AND THE ROLE OF CHANCE

Women had reduced T2* during menstrual scans versus non-menstrual scans (P = 0.005), consistent with menstrual hypoxia. Plasma flow (Fp) was increased at menstruation compared to the non-menstrual phase (P = 0.0005). Laboratory findings revealed increased ADM, VEGF-A and CXCR4 at menstruation on examination of paired endometrial biopsies from the menstrual and non-menstrual phase (P = 0.008; P = 0.03; P = 0.009). There was a significant correlation between T2* and these ex vivo hypoxic markers (P < 0.05).

LIMITATIONS, REASONS FOR CAUTION

This study examined the in vivo detection of endometrial hypoxic markers at specific timepoints in the menstrual cycle in women with a menstrual blood loss <80 ml/cycle and without significant uterine structural abnormalities. Further research is required to determine the presence of endometrial hypoxia in those experiencing abnormal uterine bleeding with and without fibroids/adenomyosis.

WIDER IMPLICATIONS OF THE FINDINGS

Heavy menstrual bleeding (HMB) is a common, debilitating condition. Understanding menstrual physiology may improve therapeutics. To our knowledge, this is the first in vivo data supporting the presence of menstrual hypoxia in the endometrium of women with normal menstrual bleeding. If aberrant in those with HMB, these non-invasive tests may aid diagnosis and facilitate personalized treatments for HMB.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by Wellbeing of Women grant RG1820, Wellcome Trust Fellowship 209589/Z/17/Z and undertaken in the MRC Centre for Reproductive Health, funded by grants G1002033 and MR/N022556/1. H.O.D.C. has clinical research support for laboratory consumables and staff from Bayer AG and provides consultancy advice (but with no personal remuneration) for Bayer AG, PregLem SA, Gedeon Richter, Vifor Pharma UK Ltd, AbbVie Inc; Myovant Sciences GmbH. H.O.D.C. receives royalties from UpToDate for articles on abnormal uterine bleeding.

TRIAL REGISTRATION NUMBER

N/A.

Physiology of the Endometrium and Regulation of Menstruation

The physiological functions of the uterine endometrium (uterine lining) are preparation for implantation, maintenance of pregnancy if implantation occurs, and menstruation in the absence of pregnancy. The endometrium thus plays a pivotal role in reproduction and continuation of our species. Menstruation is a steroid-regulated event, and there are alternatives for a progesterone-primed endometrium, i.e., pregnancy or menstruation. Progesterone withdrawal is the trigger for menstruation. The menstruating endometrium is a physiological example of an injured or “wounded” surface that is required to rapidly repair each month. The physiological events of menstruation and endometrial repair provide an accessible in vivo human model of inflammation and tissue repair. Progress in our understanding of endometrial pathophysiology has been facilitated by modern cellular and molecular discovery tools, along with animal models of simulated menses. Abnormal uterine bleeding (AUB), including heavy menstrual bleeding (HMB), imposes a massive burden on society, affecting one in four women of reproductive age. Understanding structural and nonstructural causes underpinning AUB is essential to optimize and provide precision in patient management. This is facilitated by careful classification of causes of bleeding. We highlight the crucial need for understanding mechanisms underpinning menstruation and its aberrations. The endometrium is a prime target tissue for selective progesterone receptor modulators (SPRMs). This class of compounds has therapeutic potential for the clinical unmet need of HMB. SPRMs reduce menstrual bleeding by mechanisms still largely unknown. Human menstruation remains a taboo topic, and many questions concerning endometrial physiology that pertain to menstrual bleeding are yet to be answered.

Effect of Tahiti lime (Citrus latifolia) juice on the Production of the PGF2α/PGE2 and Pro-Inflammatory Cytokines involved in Menstruation

Tahiti lemon juice (Citrus latifolia) (TLJ), as a natural source of flavonoids, has been used as an alternative to anti-inflammatory drugs for the treatment of dysmenorrhea and menstrual excessive bleeding, often associated with an imbalance of the prostaglandins (PG) levels. However, despite the positive effects, the mechanisms that rule menstruation control are still unknown. Therefore, the objectives were to characterize the TLJ and analyze its effect on the production of PGF2α, PGE2 and pro-inflammatory cytokines involved inmenstruation. Flavonoids from TLJ were discriminated by UPLC-DAD-MS/MS (Qq-TOF) and the effects of TLJ were studied in vitro by quantification of the contraction of myoblasts in culture and PGF2α and PGE2 productions. Further, the systemic and menstrual fluid levels of PGF2α, PGE2, IL-1β, TNF-α, IL-6, AK1B1 and AK1C3 enzymes produced by women during the menstrual period were compared after exposition or not to TLJ or meloxicam. The results showed that TLJ induces an increase in the contraction of myoblasts and the PGF2α supernatant level. Regarding in vivo analysis, a higher concentration of PGF2α and an unaltered PGE2 level was also found in the menstrual blood of women treated with TLJ, in contrast with a lower level of PGE2 and PGF2α observed in the meloxicam group. Concerning cytokines, only menstrual TNF-α levels decrease after treatment with TLJ or meloxicam. In conclusion, TLJ may favor the control of menstruation events via a PGF2α mediated muscle contractile response.

Non-steroidal anti-inflammatory drugs for heavy menstrual bleeding

BACKGROUND

Heavy menstrual bleeding (HMB) is an important cause of ill health in premenopausal women. Although surgery is often used as a treatment, a range of medical therapies are also available. Non-steroidal anti-inflammatory drugs (NSAIDs) reduce prostaglandin levels, which are elevated in women with excessive menstrual bleeding and also may have a beneficial effect on dysmenorrhoea.

OBJECTIVES

To determine the effectiveness, safety and tolerability of NSAIDs in achieving a reduction in menstrual blood loss (MBL) in women of reproductive years with HMB.

SEARCH METHODS

We searched, in April 2019, the Cochrane Gynaecology and Fertility specialised register, Cochrane Central Register of Studies Online (CENTRAL CRSO), MEDLINE, Embase, PsycINFO, the clinical trial registries and reference lists of articles.

SELECTION CRITERIA

The inclusion criteria were randomised comparisons of individual NSAIDs or combined with other medical therapy with each other, placebo or other medical treatments in women with regular heavy periods measured either objectively or subjectively and with no pathological or iatrogenic (treatment-induced) causes for their HMB.

DATA COLLECTION AND ANALYSIS

We identified 19 randomised controlled trials (RCTs) (759 women) that fulfilled the inclusion criteria for this review and two review authors independently extracted data. We estimated odds ratios (ORs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes from the data of nine trials. We described in data tables the results of the remaining seven cross-over trials with data unsuitable for pooling, one trial with skewed data, and one trial with missing variances. One trial had no data available for analysis.

MAIN RESULTS

As a group, NSAIDs were more effective than placebo at reducing HMB but less effective than tranexamic acid, danazol or the levonorgestrel-releasing intrauterine system (LNG IUS). Treatment with danazol caused a shorter duration of menstruation and more adverse events than NSAIDs, but this did not appear to affect the acceptability of treatment, based on trials from 1980 to 1990. However, currently danazol is not a usual or recommended treatment for HMB. There was no clear evidence of difference between NSAIDs and the other treatments (oral luteal progestogen, ethamsylate, an older progesterone-releasing intrauterine system and the oral contraceptive pill (OCP), but most studies were underpowered. There was no evidence of a difference between the individual NSAIDs (naproxen and mefenamic acid) in reducing HMB. The evidence quality ranged from low to moderate, the main limitations being risk of bias and imprecision.

AUTHORS' CONCLUSIONS

NSAIDs reduce HMB when compared with placebo, but are less effective than tranexamic acid, danazol or LNG IUS. However, adverse events are more severe with danazol therapy. In the limited number of small studies suitable for evaluation, there was no clear evidence of a difference in efficacy between NSAIDs and other medical treatments such as oral luteal progestogen, ethamsylate, OCP or the older progesterone-releasing intrauterine system.

Abnormal Uterine Bleeding: Current Classification and Clinical Management

Abnormal uterine bleeding is now classified and categorized according to the International Federation of Gynecology and Obstetrics classification system: PALM-COEIN. This applies to nongravid women during their reproductive years and allows more clear designation of causes, thus aiding clinical care and future research.

The medical management of abnormal uterine bleeding in reproductive-aged women

In the treatment of women with abnormal uterine bleeding, once a thorough history, physical examination, and indicated imaging studies are performed and all significant structural causes are excluded, medical management is the first-line approach. Determining the acuity of the bleeding, the patient's medical history, assessing risk factors, and establishing a diagnosis will individualize their medical regimen. In acute abnormal uterine bleeding with a normal uterus, parenteral estrogen, a multidose combined oral contraceptive regimen, a multidose progestin-only regimen, and tranexamic acid are all viable options, given the appropriate clinical scenario. Heavy menstrual bleeding can be treated with a levonorgestrel-releasing intrauterine system, combined oral contraceptives, continuous oral progestins, and tranexamic acid with high efficacy. Nonsteroidal antiinflammatory drugs may be utilized with hormonal methods and tranexamic acid to decrease menstrual bleeding. Gonadotropin-releasing hormone agonists are indicated in patients with leiomyoma and abnormal uterine bleeding in preparation for surgical interventions. In women with inherited bleeding disorders all hormonal methods as well as tranexamic acid can be used to treat abnormal uterine bleeding. Women on anticoagulation therapy should consider using progestin-only methods as well as a gonadotropin-releasing hormone agonist to treat their heavy menstrual bleeding. Given these myriad options for medical treatment of abnormal uterine bleeding, many patients may avoid surgical intervention.

Menstrual physiology: implications for endometrial pathology and beyond

BACKGROUND

Each month the endometrium becomes inflamed, and the luminal portion is shed during menstruation. The subsequent repair is remarkable, allowing implantation to occur if fertilization takes place. Aberrations in menstrual physiology can lead to common gynaecological conditions, such as heavy or prolonged bleeding. Increased knowledge of the processes involved in menstrual physiology may also have translational benefits at other tissue sites.

METHODS

Pubmed and Cochrane databases were searched for all original and review articles published in English until April 2015. Search terms included ‘endometrium’, ‘menstruation’, ‘endometrial repair’, ‘endometrial regeneration’ ‘angiogenesis’, ‘inflammation’ and ‘heavy menstrual bleeding’ or ‘menorrhagia’.

RESULTS

Menstruation occurs naturally in very few species. Human menstruation is thought to occur as a consequence of preimplantation decidualization, conferring embryo selectivity and the ability to adapt to optimize function. We highlight how current and future study of endometrial inflammation, vascular changes and repair/regeneration will allow us to identify new therapeutic targets for common gynaecological disorders. In addition, we describe how increased knowledge of this endometrial physiology will have many translational applications at other tissue sites. We highlight the clinical applications of what we know, the key questions that remain and the scientific and medical possibilities for the future.

CONCLUSIONS

The study of menstruation, in both normal and abnormal scenarios, is essential for the production of novel, acceptable medical treatments for common gynaecological complaints. Furthermore, collaboration and communication with specialists in other fields could significantly advance the therapeutic potential of this dynamic tissue.

Low-dose dexamethasone as a treatment for women with heavy menstrual bleeding: protocol for response-adaptive randomised placebo-controlled dose-finding parallel group trial (DexFEM)

INTRODUCTION

Heavy menstrual bleeding (HMB) diminishes individual quality-of-life and poses substantial societal burden. In HMB endometrium, inactivation of cortisol (by enzyme 11β hydroxysteroid dehydrogenase type 2 (11βHSD2)), may cause local endometrial glucocorticoid deficiency and hence increased angiogenesis and impaired vasoconstriction. We propose that 'rescue' of luteal phase endometrial glucocorticoid deficiency could reduce menstrual bleeding.

METHODS AND ANALYSIS

DexFEM is a double-blind response-adaptive parallel-group placebo-controlled trial in women with HMB (108 to be randomised), with active treatment the potent oral synthetic glucocorticoid dexamethasone, which is relatively resistant to 11βHSD2 inactivation. Participants will be aged over 18 years, with mean measured menstrual blood loss (MBL) for two screening cycles ≥50 mL. The primary outcome is reduction in MBL from screening. Secondary end points are questionnaire assessments of treatment effect and acceptability. Treatment will be for 5 days in the mid-luteal phases of three treatment menstrual cycles. Six doses of low-dose dexamethasone (ranging from 0.2 to 0.9 mg twice daily) will be compared with placebo, to ascertain optimal dose, and whether this has advantage over placebo. Statistical efficiency is maximised by allowing randomisation probabilities to 'adapt' at five points during enrolment phase, based on the response data available so far, to favour doses expected to provide greatest additional information on the dose-response. Bayesian Normal Dynamic Linear Modelling, with baseline MBL included as covariate, will determine optimal dose (re reduction in MBL). Secondary end points will be analysed using generalised dynamic linear models. For each dose for all end points, a 95% credible interval will be calculated for effect versus placebo.

ETHICS AND DISSEMINATION

Dexamethasone is widely used and hence well-characterised safety-wise. Ethical approval has been obtained from Scotland A Research Ethics Committee (12/SS/0147). Trial findings will be disseminated via open-access peer-reviewed publications, conferences, clinical networks, public lectures, and our websites.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT01769820; EudractCT 2012-003405-98.

Immunology of normal and abnormal menstruation

Normal menstruation is an inflammatory process, where the endometrial concentrations and functions of several leukocyte types can change greatly through the menstrual cycle, especially during the premenstrual and menstrual phases. These leukocytes probably have a range of functions related to mucosal protection, decidualization, embryo implantation, and the process of menstrual tissue breakdown, repair and remodeling. Some of these leukocyte changes are apparently linked to changes in the pattern of circulating leukocytes. Many immune cells have been identified in the endometrium, and those with most relevance to the processes of menstruation include uterine natural killer cells, macrophages, mast cells, neutrophils, dendritic cells and Tregs. A range of disturbances in endometrial immune cell numbers, distributions and functions, and in a range of different inflammatory and other mediators, have been identified in women with heavy menstrual bleeding or endometriosis. Sufficient evidence exists to implicate these immune changes in some of the functional disturbances and symptoms identified in these women. This field is greatly under-researched, and ripe for the wider application of modern molecular and cellular techniques in human and animal model studies.

Cyclooxygenase-2 regulated by the nuclear factor-κB pathway plays an important role in endometrial breakdown in a female mouse menstrual-like model

The role of prostaglandins (PGs) in menstruation has long been proposed. Although evidence from studies on human and nonhuman primates supports the involvement of PGs in menstruation, whether PGs play an obligatory role in the process remains unclear. Although cyclooxygenase (COX) inhibitors have been used in the treatment of irregular uterine bleeding, the mechanism involved has not been elucidated. In this study, we used a recently established mouse menstrual-like model for investigating the role of COX in endometrial breakdown and its regulation. Administration of the nonspecific COX inhibitor indomethacin and the COX-2 selective inhibitor DuP-697 led to inhibition of the menstrual-like process. Furthermore, immunostaining analysis showed that the nuclear factor (NF)κB proteins P50, P65, and COX-2 colocalized in the outer decidual stroma at 12 to 16 hours after progesterone withdrawal. Chromatin immunoprecipitation analysis showed that NFκB binding to the Cox-2 promoter increased at 12 hours after progesterone withdrawal in vivo, and real-time PCR analysis showed that the NFκB inhibitors pyrrolidine dithiocarbamate and MG-132 inhibited Cox-2 mRNA expression in vivo and in vitro, respectively. Furthermore, COX-2 and NFκB inhibitors similarly reduced endometrial breakdown, suggesting that NFκB/COX-2-derived PGs play a critical role in this process. In addition, the CD45(+) leukocyte numbers were sharply reduced following indomethacin (COX-1 and COX-2 inhibitor), DuP-697 (COX-2 inhibitor), and pyrrolidine dithiocarbamate (NFκB inhibitor) treatment. Collectively, these data indicate that NFκB/COX-2-induced PGs regulate leukocyte influx, leading to endometrial breakdown.

Non-steroidal anti-inflammatory drugs for heavy menstrual bleeding

BACKGROUND

Heavy menstrual bleeding (HMB) is an important cause of ill health in premenopausal women. Although surgery is often used as a treatment, a range of medical therapies are also available. Non-steroidal anti-inflammatory drugs (NSAIDs) reduce prostaglandin levels, which are elevated in women with excessive menstrual bleeding and also may have a beneficial effect on dysmenorrhoea.

OBJECTIVES

The primary objective of this review was to investigate the effectiveness of NSAIDs in achieving a reduction in menstrual blood loss in women of reproductive years with HMB.

SEARCH METHODS

We searched the Cochrane Menstrual Disorders & Subfertility Group trials register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and CINAHL in July 2012 and reference lists of articles. We also contacted manufacturers and researchers in the field.

SELECTION CRITERIA

The inclusion criteria were randomised comparisons of individual NSAIDs or combined with other medical therapy with either each other, placebo or other medical treatments in women with regular heavy periods measured either objectively or subjectively and with no pathological or iatrogenic (treatment-induced) causes for their heavy menstrual blood loss.

DATA COLLECTION AND ANALYSIS

Eighteen RCTs were identified that fulfilled the inclusion criteria for this review and data were extracted independently. Odds ratios for dichotomous outcomes and weighted mean differences for continuous outcomes were estimated from the data of nine trials. The results of the remaining seven cross-over trials with data unsuitable for pooling, one trial with skewed data and one trial with missing variances were described in data tables.

MAIN RESULTS

As a group, NSAIDs were more effective than placebo at reducing HMB but less effective than either tranexamic acid, danazol or the levonorgestrel-releasing intrauterine system (LNG IUS). Treatment with danazol caused a shorter duration of menstruation and more adverse events than NSAIDs but this did not appear to affect the acceptability of treatment. There were no statistically significant differences between NSAIDs and the other treatments (oral luteal progestogen, ethamsylate, an older progesterone-releasing intrauterine system (Progestasert), oral contraceptive pill (OCC)) but most studies were underpowered. There was no evidence of a difference between the individual NSAIDs (naproxen and mefenamic acid) in reducing HMB.

AUTHORS' CONCLUSIONS

NSAIDs reduce HMB when compared with placebo but are less effective than tranexamic acid, danazol or LNG IUS. However, adverse events are more severe with danazol therapy. In the limited number of small studies suitable for evaluation, no significant difference in efficacy was demonstrated between NSAIDs and other medical treatments such as oral luteal progestogen, ethamsylate, OCC or another type of intrauterine system, Progestasert.

Abnormal uterine bleeding and dysfunctional uterine bleeding in pediatric and adolescent gynecology

Abnormal uterine bleeding (AUB), which is defined as excessively heavy, prolonged and/or frequent bleeding of uterine origin, is a frequent cause of visits to the Emergency Department and/or health care provider. While there are many etiologies of AUB, the one most likely among otherwise healthy adolescents is dysfunctional uterine bleeding (DUB), which is characterizing any AUB when all possible underlying pathologic causes have been previously excluded. The most common cause of DUB in adolescence is anovulation, which is very frequent in the first 2-3 post-menarchal years and is associated with immaturity of the hypothalamic - pituitary - ovarian axis. Management of AUB is based on the underlying etiology and the severity of the bleeding and primary goals are prevention of complications, such as anemia and reestablishment of regular cyclical bleeding, while the management of DUB can in part be directed by the amount of flow, the degree of associated anemia, as well as patient and family comfort with different treatment modalities. Treatment options for DUB are: combined oral contraceptives (COCs), progestogens, non steroidal anti inflammatory drugs (NSAIDs), tranexamic acid (anti-fibrinolytic), GnRH analogues, Danazol and Levonorgestrel releasing intra uterine system (LNG IUS).

Classification of menstrual bleeding disorders

There exists a spectrum of potential causes of abnormal uterine bleeding (AUB) in nonpregnant reproductive-aged women. In some instances the abnormal bleeding may emanate from definable pathologic entities in the endometrial cavity such as polyps or submucous leiomyomas (fibroids), while in others, it may occur secondary to coagulopathies or disorders of local or systemic hemostasis. If the patient is subjected to a rigorous evaluation more than one potential contributor may be identified, a circumstance that challenges the clinician since entities such as polyps, leiomyomas, and adenomyosis may frequently be asymptomatic, even in women with AUB. The bench or clinical investigator may also be influenced by the existence of the multiplicity of potential causes that could confound the results of research. This paper describes FIGO's (Fédération Internationale de Gynécologie et d'Obstétrique) new PALM-COEIN classification of causes of AUB in the reproductive years (Polyp, Adenomyosis, Leiomyoma, Malignancy and hyperplasia-Coagulopathy, Ovulatory disorder, Endometrial, Iatrogenic, Not yet classified). This system is designed to assist clinicians in the evaluation of patients, investigators in the design and interpretation of research and faculty in the education of medical students and residents/trainees. Additionally, given the longstanding existence of a confusing array of conflicting definitions, the manuscript describes the FIGO standardized terminology for both normal menstruation and AUB symptoms.

Pulmonary arterial hypertension: classification and therapy with a focus on prostaglandin analogs

Pulmonary arterial hypertension, part of the larger spectrum of disorders causing pulmonary hypertension, is a complex and progressive disease of multiple etiologies that ultimately leads to vascular remodeling, right-sided heart failure, and death. Advances in treatment over the past 15 to 20 years have dramatically reduced the morbidity and mortality of the disease, but often have significant drawbacks. Of the more recently approved therapies, the prostaglandin analogs have been shown to have the greatest therapeutic benefit but are also the most difficult to administer, many being given as continuous intravenous infusions in the ambulatory setting. After a case presentation highlighting some of the challenges that accompany treatment with these agents, this article reviews the diagnosis and classification of pulmonary hypertension and pulmonary arterial hypertension and gives a brief overview of the various other pharmacologic agents used in its treatment. A more comprehensive review of the biochemistry of prostaglandins and the pharmacology and clinical use of this class of drugs follows. Recommended treatment guidelines are also discussed.

The FIGO systems for nomenclature and classification of causes of abnormal uterine bleeding in the reproductive years: who needs them?

In November 2010, the International Federation of Gynecology and Obstetrics formally accepted a new classification system for causes of abnormal uterine bleeding in the reproductive years. The system, based on the acronym PALM-COEIN (polyps, adenomyosis, leiomyoma, malignancy and hyperplasia-coagulopathy, ovulatory disorders, endometrial causes, iatrogenic, not classified) was developed in response to concerns about the design and interpretation of basic science and clinical investigation that relates to the problem of abnormal uterine bleeding. A system of nomenclature for the description of normal uterine bleeding and the various symptoms that comprise abnormal bleeding has also been included. This article describes the rationale, the structured methods that involved stakeholders worldwide, and the suggested use of the International Federation of Gynecology and Obstetrics system for research, education, and clinical care. Investigators in the field are encouraged to use the system in the design of their abnormal uterine bleeding-related research because it is an approach that should improve our understanding and management of this often perplexing clinical condition.

Tranexamic acid for the treatment of heavy menstrual bleeding: efficacy and safety

Tranexamic acid has proven to be an effective treatment for heavy menstrual bleeding (HMB). It reduces menstrual blood loss (MBL) by 26%-60% and is significantly more effective than placebo, nonsteroidal anti-inflammatory drugs, oral cyclical luteal phase progestins, or oral etamsylate, while the levonorgestrel-releasing intrauterine system reduces MBL more than tranexamic acid. Other treatments used for HMB are oral contraceptives, danazol, and surgical interventions (endometrial ablation and hysterectomy). Medical therapy is usually considered a first-line treatment for idiopathic HMB. Tranexamic acid significantly improves the quality of life of women treated for HMB. The recommended oral dosage is 3.9-4 g/day for 4-5 days starting from the first day of the menstrual cycle. Adverse effects are few and mainly mild. No evidence exists of an increase in the incidence of thrombotic events associated with its use. An active thromboembolic disease is a contraindication. In the US, a history of thrombosis or thromboembolism, or an intrinsic risk for thrombosis or thromboembolism are considered contraindications as well. This review focuses on the efficacy and safety of tranexamic acid in the treatment of idiopathic HMB. We searched for medical literature published in English on tranexamic acid from Ovid Medline, PubMed, and Cinahl. Additional references were identified from the reference lists of articles. Ovid Medline, PubMed, and Cinahl search terms were "tranexamic acid" and "menorrhagia" or "heavy menstrual bleeding." Searches were last updated on March 25, 2012. Studies with women receiving tranexamic acid for HMB were included; randomized controlled studies with a description of appropriate statistical methodology were preferred. Relevant data on the physiology of menstruation and the pharmacodynamics and pharmacokinetics of tranexamic acid are also included.

Insight: prolonged vaginal bleeding during central precocious puberty therapy with a long-acting gonadotropin-releasing hormone agonist: a proposed mechanism and management plan

We have previously described our data collected after administration of gonadotropin releasing hormone-agonist (GnRH-a) to delay sexual maturation, in premenarchal girls suffering from idiopathic central precocious puberty.(1) We have explained the recurrent episodes of bleeding due to discontinuation of the estrogen support of the proliferative and stable endometrium. The recognition in recent years of the extra-pituitary functions of GnRH-a, the ability of GnRH to stimulate prostaglandin production and the known role of prostaglandins in irregular vaginal bleeding prompted us to seek alternative explanations to our data. We suggest considering a potential clinical use of combination therapies of GnRH agonists and prostanoid receptor antagonists to treat central precocious puberty.

The regulation of vascular endothelial growth factor by hypoxia and prostaglandin F₂α during human endometrial repair

CONTEXT

The human endometrium has an exceptional capacity for repeated repair after menses, but its regulation remains undefined. Premenstrually, progesterone levels fall and prostaglandin (PG) F₂α synthesis increases, causing spiral arteriole constriction. We hypothesized that progesterone withdrawal, PGF₂α, and hypoxia increase vascular endothelial growth factor (VEGF), an endometrial repair factor.

DESIGN AND RESULTS

Endometrial biopsies were collected (n = 47) with ethical approval and consent. VEGF mRNA, quantified by quantitative RT-PCR, was increased during menstruation (P < 0.01).VEGF protein was maximally secreted from proliferative endometrial explants. Treatment of an endometrial epithelial cell line and primary human endometrial stromal cells with 100 nm PGF₂α or hypoxia (0.5% O₂) resulted in significant increases in VEGF mRNA and protein. VEGF was maximal when cells were cotreated with PGF(2α) and hypoxia simultaneously (P < 0.05-0.001). Secretory-phase endometrial explants also showed an increase in VEGF with cotreatment (P < 0.05). However, proliferative-phase explants showed no increase in VEGF on treatment with PGF₂α and/or hypoxia. Proliferative tissue was induced to increase VEGF mRNA expression when exposed to progesterone and its withdrawal in vitro but only in the presence of hypoxia and PG. Hypoxia-inducible factor-1α (HIF-1α) silencing with RNA interference suppressed hypoxia-induced VEGF expression in endometrial cells but did not alter PGF₂α-induced VEGF expression.

CONCLUSIONS

Endometrial VEGF is increased at the time of endometrial repair. Progesterone withdrawal, PGF₂α, and hypoxia are necessary for this perimenstrual VEGF expression. Hypoxia acts via HIF-1α to increase VEGF, whereas PGF₂α acts in a HIF-1α-independent manner. Hence, two pathways regulate the expression of VEGF during endometrial repair.

The FIGO classification of causes of abnormal uterine bleeding in the reproductive years

At this juncture, clinical management, education for medical providers, and the design and interpretation of clinical trials have been hampered by the absence of a consensus system for nomenclature for the description of symptoms as well as classification of causes or potential causes of abnormal uterine bleeding (AUB). To address this issue, the Fédération Internationale de Gynécologie et d'Obstétrique (FIGO) has designed the PALM-COEIN (Polyp, Adenomyosis, Leiomyoma, Malignancy and Hyperplasia, Coagulopathy, Ovulatory Disorders, Endometrial Disorders, Iatrogenic Causes, and Not Classified) classification system for causes of AUB in the reproductive years.

FIGO classification system (PALM-COEIN) for causes of abnormal uterine bleeding in nongravid women of reproductive age

There is general inconsistency in the nomenclature used to describe abnormal uterine bleeding (AUB), in addition to a plethora of potential causes-several of which may coexist in a given individual. It seems clear that the development of consistent and universally accepted nomenclature is a step toward rectifying this unsatisfactory circumstance. Another requirement is the development of a classification system, on several levels, for the causes of AUB, which can be used by clinicians, investigators, and even patients to facilitate communication, clinical care, and research. This manuscript describes an ongoing process designed to achieve these goals, and presents for consideration the PALM-COEIN (polyp; adenomyosis; leiomyoma; malignancy and hyperplasia; coagulopathy; ovulatory dysfunction; endometrial; iatrogenic; and not yet classified) classification system for AUB, which has been approved by the International Federation of Gynecology and Obstetrics (FIGO) Executive Board as a FIGO classification system.

Inflammatory pathways in endometrial disorders

Complex interactions between the endocrine and immune systems govern the key endometrial events of implantation and menstruation. In contrast to other tissue sites, cyclical endometrial inflammation is physiological. However, dysregulation of this inflammatory response can lead to endometrial disorders. This review examines the inflammatory processes occurring in the normal endometrium during menstruation and implantation, highlighting recent advances in our understanding and gaps in current knowledge. Subsequently, the role of inflammatory pathways in the pathology of various common endometrial conditions is discussed, including heavy menstrual bleeding, dysmenorrhoea (painful periods), uterine fibroids, endometriosis and recurrent miscarriage.

Progesterone: a pivotal hormone at menstruation

The human endometrium is exposed to repeated inflammation every month, culminating in tissue breakdown and menstruation. Subsequently, the endometrium has a remarkable capacity for efficient repair and remodeling to enable implantation if fertilization takes place. Endometrial function is known to be governed by the ovarian hormones estradiol and progesterone. This review paper focuses on hormonal control of the cyclical tissue injury and repair that takes place in the local endometrial environment at the time of menstruation. Progesterone levels decline premenstrually as the corpus luteum regresses in the absence of pregnancy, and estradiol levels increase during the postmenstrual phase. The functional impact of these significant changes is discussed, including their immediate and downstream effects. Finally, we examine the contribution of aberrant endometrial function to the presentation of heavy menstrual bleeding and identify potential therapeutic targets for the treatment of this common gynecological problem.

Comprehensive expression analysis of prostanoid enzymes and receptors in the human endometrium across the menstrual cycle

Prostanoids are well-described primary mediators of inflammatory processes and are essential for the normal physiological function of the female reproductive system. The aim of this study was to determine the temporal expression of the prostanoid biosynthetic enzymes (PTGS1, PTGS2, PTGES, PTGES2, PTGES3, AKR1B1, AKR1C3, CBR1, HPGDS, PTGDS, PTGIS, TBXAS1 and HPGD) and the prostanoid receptors (PTGER1, PTGER2, PTGER3, PTGER4, PTGFR, PTGDR, GPR44, PTGIR and TBXA2R) in the human endometrium throughout the menstrual cycle. The analysis identified PTGFR to have a distinct expression profile compared with other components of the prostanoid system, as expression is maximal during the proliferative phase. Immunohistochemical analysis for PTGER1 suggests a dual function for this receptor depending on its temporal (proliferative versus secretory) and spatial (nuclear versus cell membrane) expression. The expression profiles of the PGF(2α) synthases identified AKR1B1 and CBR1 as the likely regulators of PGF(2α) production during the menstrual phase. Immunohistochemical analysis for AKR1B1, CBR1 and AKR1C3 suggest expression to be in the glandular epithelium and vasculature. This study represents the first comprehensive analysis of the components of prostanoid biosynthetic and signalling pathway in the human endometrium. The expression profiles described have the potential to identify specific prostanoid components that may be dysregulated in inflammatory-associated disorders of the endometrium.

Novel roles for hypoxia and prostaglandin E2 in the regulation of IL-8 during endometrial repair

The endometrium has a remarkable capacity for efficient repair; however, factors involved remain undefined. Premenstrual progesterone withdrawal leads to increased prostaglandin (PG) production and local hypoxia. Here we determined human endometrial expression of interleukin-8 (IL-8) and the roles of PGE(2) and hypoxia in its regulation. Endometrial biopsy specimens (n = 51) were collected. Endometrial cells and explants were exposed to 100 nmol/L of PGE(2) or 0.5% O(2). The endometrial IL-8 concentration peaked during menstruation (P < 0.001) and had a significant proangiogenic effect. IL-8 was increased by PGE(2) and hypoxia in secretory but not proliferative explants, which suggests that exposure to progesterone is essential. In vitro progesterone withdrawal induced significant IL-8 up-regulation in proliferative explants primed with progestins, but only in the presence of hypoxia. Epithelial cells treated simultaneously with PGE(2) and hypoxia demonstrated synergistic increases in IL-8. Inhibition of HIF-1 by short hairpin RNA abolished hypoxic IL-8 induction, and inhibition of NF-κB by an adenoviral dominant negative inhibitor decreased PGE(2)-induced IL-8 expression (P > 0.05). Increased menstrual IL-8 is consistent with a role in repair. Progesterone withdrawal, hypoxia, and PGE(2) regulate endometrial IL-8 by acting via HIF-1 and NF-κB. Hence, progesterone withdrawal may activate two distinct pathways to initiate endometrial repair.

Role of Non-Steroidal Anti-Inflammatory Drugs in Gynecology

This review summarizes the current use of non-steroidal anti-inflammatory drugs (NSAIDs) in obstetrics, gynecology and infertility. These medications are commonly used in different fields of reproductive medicine, for pain management after operative procedures and to relieve dysmenorrhea. In addition to their analgesic effect, NSAIDs are helpful in the management of menorrhagia by decreasing menstrual blood loss. NSAIDs alleviate pain associated with medical abortion, assist in undertaking natural cycle in-vitro fertilization by preventing follicular rupture and reducing premature ovulation, and serve as tocolytics in preterm labor. New NSAIDs may have a growing role in management of women's health.

Levonorgestrel Intrauterine System: A First-Line Medical Treatment for Heavy Menstrual Bleeding

Chronic heavy menstrual bleeding is a common gynecologic condition that causes significant health problems and negatively impacts a woman's quality of life. Surgical treatments should be reserved for women who have pelvic pathology and for those who fail medical therapy. The recent US FDA approval of the levonorgestrel-releasing intrauterine system as an indicated treatment for heavy menstrual bleeding in women who want to use intrauterine devices for birth control highlights the potential that this top tier contraceptive method offers as a first-line therapy for treatment of this problem in women of any reproductive age, without sacrificing their future fertility.

EP2 receptor mediated cAMP release is augmented by PGF 2 alpha activation of the FP receptor via the calcium-calmodulin pathway

Prostaglandins exert their effects on target cells by coupling to specific G protein-coupled receptors (GPCRs) that are often co-expressed in the same cells and use alternate and in some cases opposing intracellular signaling pathways. This study investigated the cross-talk that influences intracellular signaling and gene expression profiling in response to co-activation of the EP2 and FP prostanoid receptors in Ishikawa cells stably expressing both receptors (FPEP2 cells). In this study we show that in FPEP2 cells, PGF alone does not alter adenosine 3',5'-cyclic monophosphate (cAMP) production, but in combination with Butaprost enhances EP2 receptor mediated cAMP release compared to treatment with Butaprost alone. PGF-mediated potentiation of cAMP release was abolished by antagonism of the FP receptor, inhibition of phospholipase C (PLC) and inositol phosphate receptor (IP3R) whereas inhibition of protein kinase C (PKC) had no effect. Moreover, inhibition of calcium effectors using calmodulin antagonist (W7) or Ca(2+)/calmodulin-dependent kinase II (CaMK-II) inhibitor (KN-93) abolished PGF potentiation of Butaprost-mediated cAMP release. Using siRNA molecules targeted against the adenylyl cyclase 3 (AC3) isoform, we show that AC3 is responsible for the cross-talk between the FP and EP2 receptors. Using gene array studies we have identified a candidate gene, Spermidine/N1-acetyltransferase (SAT1), which is regulated by this cAMP mediated cross-talk. In conclusion, this study demonstrates that co-activation of the FP and EP2 receptors results in enhanced release of cAMP via FP receptor-G alpha(q)-Ca(2+)-calmodulin pathway by activating calcium sensitive AC3 isoform.

Cortisol inactivation by 11beta-hydroxysteroid dehydrogenase-2 may enhance endometrial angiogenesis via reduced thrombospondin-1 in heavy menstruation

CONTEXT

Heavy menstrual bleeding (HMB; menorrhagia) impairs quality of life for women and requires medication or surgery. Because glucocorticoids inhibit angiogenesis in other organs, we hypothesized that endometrium of women with HMB is subject to decreased local glucocorticoid exposure and enhanced angiogenesis, thereby increasing menstrual bleeding.

DESIGN

Endometrium was collected from 29 women with menstrual complaints. Menstrual blood loss was measured by alkaline-hematin assay (n = 12, > 80 ml (HMB); n = 17, < 80 ml). Quantitative RT-PCR for thrombospondin-1 (TSP-1) and glucocorticoid-metabolizing enzymes, 11beta-hydroxysteroid dehydrogenases-1 and -2 (11betaHSD1,2) was performed. Glucocorticoid effects on endometrial stromal cells and uterine endothelial cells (UECs) were determined. RNA interference studies in UECs examined the effect of TSP-1 ablation on cortisol action.

RESULTS

Secretory phase endometrium mRNA levels for the cortisol inactivating enzyme 11betaHSD2 were higher [3.78 +/- 1.29 vs. 1.40 +/- 0.6 (arbitrary units), P < 0.05], whereas TSP-1 mRNA was lower [0.40 +/- 0.13 vs. 1.66 +/- 1.02 (arbitrary units), P < 0.05] in women with HMB. In cultured endometrial stromal cells and UECs, cortisol increased TSP-1 expression. Both cortisol and TSP-1 inhibited new vessel formation in endometrial explants embedded in Matrigel. In UECs cortisol inhibition of tube-like structure formation was blocked by small interfering RNA (siRNA) against TSP-1 (25 +/- 2.5% cortisol inhibition with scrambled siRNA vs. 0% cortisol inhibition with TSP-1 siRNA inactivation, P<0.01).

CONCLUSIONS

Enhanced inactivation of cortisol by 11betaHSD2 in endometrium from women with HMB may explain reduced TSP-1 levels and hence endothelial cell dysfunction and abnormal angiogenesis. Inhibition of 11betaHSD2 may be a rational novel therapy for heavy menstrual bleeding.

Prostaglandin F2alpha stimulates 11Beta-hydroxysteroid dehydrogenase 1 enzyme bioactivity and protein expression in bovine endometrial stromal cells

11Beta-hydroxysteroid dehydrogenase (HSD11B) enzymes have important roles in regulating cortisol availability in target tissues. We previously demonstrated that HSD11B1 is expressed and active in bovine endometrium and that cortisol suppresses prostaglandin (PG) F2alpha and PGE2 production in cultured bovine endometrial stromal cells. The present study was conducted to examine whether locally synthesized PGF2alpha and/or PGE2 regulates the enzymatic bioactivity and/or the expression of HSD11B1 in bovine endometrium. The conversion rate of cortisone to cortisol in cultured endometrial stromal cells was significantly stimulated by PGF2alpha (1 and 10 microM). In a dose-dependent manner, PGF2alpha but not PGE2 increased the net conversion of cortisone to cortisol in stromal cells after 4 h of treatment. In addition, the bioactivity of HSD11B1 was significantly inhibited by indomethacin (10 microM). The inhibitory effect of indomethacin on HSD11B1 bioactivity was abolished by PGF2alpha (1 microM) but not by PGE2. Although PGF2alpha (1 microM) did not affect the expression of HSD11B1 mRNA in cultured stromal cells, it significantly stimulated the protein expression of HSD11B1. Cycloheximide, a general translational inhibitor, abolished the stimulatory effects of PGF2alpha on HSD11B1 protein expression in endometrial stromal cells, indicating that PGF2alpha increases HSD11B1 protein expression by stimulating a posttranscriptional process rather than a transcriptional mechanism. These results demonstrate that PGF2alpha but not PGE2 increases HSD11B1 bioactivity and protein expression by stimulating a posttranscriptional mechanism in stromal cells and suggest that cortisol has a physiologically relevant role in preventing excessive uterine PG production in nonpregnant bovine endometrium.

Altered responsiveness of small uterine arteries in women with idiopathic menorrhagia

OBJECTIVE

This study was undertaken to study vascular reactivity of small myometrial arteries in women with idiopathic menorrhagia.

STUDY DESIGN

Small myometrial arteries were isolated from 6 patients with idiopathic menorrhagia and 4 controls. The contractile responses to thromboxane mimetic (U46619) and endothelin-1 were assessed before and after incubation with N(w)-nitro-L arginine methyl ester alone or in combination with indomethacin (Indo). Endothelium-dependent dilation to bradykinin and basal tension were compared before and after incubation with N(w)-nitro-L arginine methyl ester alone, or with N(w)-nitro-L arginine methyl ester in combination with indomethacin.

RESULTS

Constriction to endothelin-1 was enhanced in idiopathic menorrhagia arteries (P < .05). Idiopathic menorrhagia arteries demonstrated enhanced basal tension after incubation with N(w)-nitro-L arginine methyl ester, which was further exaggerated by indomethacin. NOS inhibition had no effect on basal tension in controls, but basal tension was enhanced after inhibition of cyclooxygenase-derived products (P < .05). Bradykinin-mediated dilation was significantly increased in idiopathic menorrhagia (P < .05).

CONCLUSION

The presence of functional alterations in small myometrial arteries could contribute to idiopathic menorrhagia.

Non-contraceptive health benefits of oral contraceptives

The use of combined oral contraceptives (COCs) is associated with a reduced risk of developing endometriosis, myomas, and endometrial and ovarian carcinoma. The mechanisms involved are multiple; next to ovulation suppression, a reduction in inflammation in the genital tract is involved. This is accomplished through inhibition of the endometrial expression of enzymes related to the biosynthesis of prostaglandin and oestrogen, particularly cyclooxygenase type II (Cox-2) and aromatase. The blockade of these enzymatic systems by COCs explains the beneficial effects of these compounds in treating the symptoms, and halting the progression of myomas, endometriosis and adenomyosis, all of which are characterized by increased inflammation. Inhibition of aromatase and Cox-2 expression in the endometrium by COCs may explain their efficacy in controlling the pain and excessive uterine bleeding caused by these pathologies. The reduction of inflammation in the endometrium may also be the mechanism behind the lower incidence of endometrial carcinoma in COC users. The blockade of ovulation and ovarian steroidogenesis, on the other hand, may explain the lesser incidence of ovarian cancer and the improvement of acne in users. In conclusion, inflammation appears to play a pivotal role in the development of various benign and malignant gynecological diseases. COCs reduce inflammation in the female genital tract by blocking enzymes such as Cox-2 and aromatase.

Prostaglandin E2 and F2alpha activate the FP receptor and up-regulate cyclooxygenase-2 expression via the cyclic AMP response element

In endometrial adenocarcinomas COX-2 and F-series prostanoid (FP) receptor expression and prostanoid biosynthesis (PGE(2) and PGF(2alpha)) are elevated. In the present study, we investigated the effect of PGE(2) and PGF(2alpha) on the expression of COX-2 via the FP receptor in endometrial adenocarcinoma cells stably expressing the FP receptor (FPS cells). Using chemical inhibitors of intracellular signaling pathways, reporter gene assays and quantitative RT-PCR analysis, we show that PGE(2) and PGF(2alpha) can mobilize inositol 1,4,5-trisphosphate, induce ERK1/2 phosphorylation via the phospholipase Cbeta-protein kinase A-epidermal growth factor receptor pathway and induce cyclooxygenase-2 (COX-2) expression via the FP receptor. In addition we show that the PGE(2) or PGF(2alpha)-regulation of COX-2 via the FP receptor is mediated via the cAMP response element (CRE) binding site on the COX-2 promoter. These data indicate that PGE(2) and PGF(2alpha) biosynthesized locally within endometrial adenocarcinomas can regulate tumor cell function in an autocrine/paracrine manner via the FP receptor.