Human endometrial prostaglandin E2 binding sites and their profiles during the menstrual cycle and in pathologic states

Menstrually associated migraine

Menstrually related migraine is a disabling condition affecting 35% to 54% females with migraine during their fertile years. The International Headache Classification distinguishes menstrually related migraine from pure menstrual migraine based on the occurrence of the attacks even outside the perimenstrual periods. Hormonal fluctuations are the main driver for the disease in subjects with genetic susceptibility and alterations of brain structures and connectivity. Menstrually related attacks are often particularly severe and disabling requiring proper management. Acute treatment mainly consists of nonsteroidal anti-inflammatory drugs (NSAIDs), recommended in patients also suffering from dysmenorrhea, and triptans. Prevention is specifically indicated in women with high monthly headache frequency or burdensome attacks during perimenstrual periods. Trials proved the efficacy of short-term prevention with triptans and NSAIDs but did not evaluate possible long-term effectiveness and tolerability. Evidence of prevention using hormonal treatments is poor, but extended-cycle treatments might be suitable for women requiring hormonal replacement for concomitant conditions. Few data are available on treatments targeting CGRP, among whom gepants are the most promising because of their utility both in migraine acute and preventive treatment. A greater recognition of disease and a deep knowledge of patients' comorbidities are essential to its proper management.

A cyclic pain: the pathophysiology and treatment of menstrual migraine

Catamenial migraine is a headache disorder occurring in reproductive-aged women relevant to menstrual cycles. Catamenial migraine is defined as attacks of migraine that occurs regularly in at least 2 of 3 consecutive menstrual cycles and occurs exclusively on day 1 to 2 of menstruation, but may range from 2 days before (defined as -2) to 3 days after (defined as +3 with the first day of menstruation as day +1). There are 2 subtypes: the pure menstrual migraine and menstrually related migraine. In pure menstrual migraine, there are no aura and no migraine occurring during any other time of the menstrual cycle. In contrast, menstrually related migraine also occurs in 2 of 3 consecutive menstrual cycles, mostly on days 1 and 2 of menstruation, but it may occur outside the menstrual cycle. Catamenial migraine significantly interferes with the quality of life and causes functional disability in most sufferers. The fluctuation of estrogen levels is believed to play a role in the pathogenesis of catamenial migraine. In this review, we discuss estrogen and its direct and indirect pathophysiologic roles in menstrual-related migraine headaches and the available treatment for women.

TARGET AUDIENCE

Obstetricians and gynecologists, family physicians.

LEARNING OBJECTIVES

After completing this CME activity, physicians should be better able to discuss the pathophysiology of catamenial migraine, identify the risk factors for catamenial migraine among women, and list the prophylactic and abortive treatments for migraines.

Management of Heavy Menstrual Bleeding: Is Hysterectomy the Radical Mastectomy of Gynecology?

Both hysterectomy for heavy menstrual bleeding and radical mastectomy for breast cancer are steeped in the history of surgery and have recently been challenged as being too radical for the disorder at hand. Radical mastectomy has largely been replaced with local removal of the tumor with subsequent radiation and/or chemotherapy. Alternatives to hysterectomy include a number of medical interventions, most notably intrauterine progestin-releasing systems, and endometrial ablation, a procedure that has a relatively high success rate and one that is now feasible for many women in an office or procedure room setting. However, although radical mastectomy rates have dropped precipitously, hysterectomy rates, at least in the United States remain relatively stable. Determining the proportion of hysterectomies that are done for heavy menstrual bleeding is difficult, largely because of coding issues, so it is difficult to measure the impact of new medical and minimally invasive surgical procedures. Nevertheless, it seems clear that many women are not exposed to the plethora of options to hysterectomy, a fact that may reflect a number of issues that may include training, skill, and financial incentives or disincentives. Clearly, options to hysterectomy are not a panacea, but if women are empowered to select from all of the options available, the rate of hysterectomy for bleeding should decrease while maintaining, or even enhancing the patient's satisfaction with care.

Endometrial Ablation: Where Have We Been? Where Are We Going?

Endometrial ablation (EA) is targeted destruction of the endothelial surface of the uterine cavity. The procedure was originally designed as a less invasive alternative to hysterectomy for the symptom of heavy menstrual bleeding unrelated to structural pathology of the uterus, that was not responsive to medical therapy. More recently it has become apparent that the procedure can be performed in the presence of submucous leiomyomas, providing they meet a number of size and location criteria. The first EA serie as published in Germany in the 1930s, but the procedure did not attract much attention until the latter part of the 20th century. Currently, EA can be performed under endoscopic direction with the neodymium:yttrium alumnum garnet laser, with a radiofrequency resectoscope, or with an expanding array of nonresectoscopic EA systems. It is apparent that most but not all of the complications associated with resectoscopic endometrial ablation are eliminated with nonresectoscopic endometrial ablation, but serious morbidity has been reported with all of the newer systems to date. Success and patient satisfaction seem to be enduring in the majority of well-selected patients treated in clinical trials, but repeat surgery, usually hysterectomy, is performed in 25% to 40% by 5 years after surgery. Increased efficiencies should be realized if the procedure could be moved to an office setting.

Resveratrol interferes with AKT activity and triggers apoptosis in human uterine cancer cells

Background

Endometrial cancer is the fourth most prominent cancer among all feminine cancers in the Western world. Resveratrol, a natural anti-oxidant found in red wine emerging as a novel anticancer agent, exerts antiproliferative and pro-apoptotic activity in various cancer cell types, but its effect on uterine cancer cells is poorly understood. At the molecular level, resveratrol has been reported to inhibit cyclooxygenase (COX) expression and/or activity; in endometrial cancer cells, COX-2 is overexpressed and confers cellular resistance to apoptosis. The aim of the present study was to determine if resveratrol could exert anti-proliferative and pro-apoptotic activity over uterine cancer cells upon inhibition of COX-2 expression and/or activity. Six different human uterine cancer cell lines were used as a model (HeLa, Hec-1A, KLE, RL95-2, Ishikawa and EN-1078D).

Results and discussion

High-dose of resveratrol triggered apoptosis in five out of six uterine cancer cell lines, as judged from Hoechst nuclear staining and effector caspase cleavage. In accordance, uterine cancer cell proliferation was decreased. Resveratrol also reduced cellular levels of the phosphorylated/active form of anti-apoptotic kinase AKT. Endogenous COX-2 protein levels were decreased, concomitant with a decrease in production of COX metabolites PGE2 and PGF2α, in each uterine cancer cell line expressing detectable levels of COX-1 and/or COX-2 in presence of resveratrol. Although COX expression was identified as a target of resveratrol in uterine cancer cells, inhibition of COX activity or exogenously added PGE2 did not modulate the effect of resveratrol on cellular proliferation.

Conclusion

High-dose of resveratrol exerts tumoricidal activity over uterine cancer cells and regulates COX expression. In these cells, resveratrol would not directly target COX activity, but possibly other enzymes involved in prostaglandin synthesis that act downstream of the COXs.

Targeted disruption of LH receptor gene revealed the importance of uterine LH signaling

Numerous previous studies have demonstrated that LH and hCG can directly regulate several uterine functions. We investigated in the present study, whether uterine phenotype in LH receptor knockout animals resulted also from the absence of direct actions of LH in the uterus. The phenotype consisted of marked growth reduction of uterus, decreased thickness of endometrial and myometrial layers, number of endometrial glands, height of luminal epithelium and vascular space. Analysis of uterine gene expression by mouse genome U74Av2 Affymetrix genechips revealed a differential expression of 155 genes by more than 3-fold (range 3-53-fold) between null and wild-type animals. Of these, 89 genes decreased and 66 increased in uterus of null animals. Semi-quantitative RT-PCR confirmed the differential expression of several selected genes. The decreased genes can be clustered into 18 functional families and the increased into 15 functional families. Semi-quantitative RT-PCR, Western blotting and immunocytochemistry demonstrated a decreased expression of ERbeta, PR-A, PR-B and AR in uterus of null animals as compared with wild-type siblings. Twenty-one-day estradiol and progesterone replacement therapy did not normalize the decrease in the number of endometrial glands and several genes that either decreased or increased in expression. The partial success of therapy suggests that direct LH actions could be required to completely normalize the uterus. In summary, findings on the knockout model reaffirm that LH and hCG control uterine functions directly as well as indirectly through increasing ovarian synthesis of steroid hormones and both actions are required for normal uterine biology.

Dysfunctional uterine bleeding: advances in diagnosis and treatment

Dysfunctional uterine bleeding occurs during the reproductive years unrelated to structural uterine abnormalities. Ovulatory dysfunctional uterine bleeding occurs secondary to defects in local endometrial hemostasis; while anovulatory dysfunctional uterine bleeding is a systemic disorder, occurring secondary to endocrinologic, neurochemical, or pharmacologic mechanisms. Evaluation of patients with abnormal uterine bleeding and identifying those with dysfunctional uterine bleeding is achieved with a combination of the following: history; physical examination; and judicious use of laboratory evaluation, endometrial sampling and uterine imaging, with sonographic techniques and/or hysteroscopy. Coagulopathies should be considered as should the notion that intramural and subserosal myomas are unlikely to contribute to AUB. High-quality evidence suggests that medical therapy is frequently successful, and newer approaches, such as local delivery of progestins via intrauterine devices, appear to be particularly promising and devoid of systemic side effects. For those intolerant of medical therapy, and/or for whom fertility is no longer desired, a number of minimally invasive surgical options for hysterectomy now exist and are collectively termed endometrial ablation. Endometrial ablation may be performed with or without hysteroscopic guidance. There is an increasing body of evidence that suggests that nonhysteroscopic endometrial ablation may be at least as effective as hysteroscopic endometrial ablation, even when the hysteroscopic procedure is performed by experts.

Medical management of abnormal uterine bleeding

Abnormal uterine bleeding occurs secondary to a wide variety of functional and structural abnormalities. Although there is clearly a place for surgery, medical therapy has enormous potential for most women, especially those with dysfunctional uterine bleeding. To provide women with appropriate options for therapy, the clinician must be prepared to distinguish abnormal bleeding that is associated with ovulation from that which is anovulatory and to use appropriate ancillary tests to identify structural and endocrinologic anomalies or lifestyle factors that may explain the bleeding. In undertaking such an investigation, it is important for the clinician to be able to distinguish lesions that may be asymptomatic and unrelated to the bleeding from those that truly are the source of the problem. With this information, a rationally determined set of medical and, if appropriate, surgical therapeutic options may be presented to the woman. Among these medical treatment options are a number of treatment options that have not seen widespread use in North America but are inexpensive, effective, and well tolerated. It is clear that medical therapy is not for everyone. Women deserve the opportunity to relieve their symptoms with nonsurgical options.

Tenoxicam versus lynestrenol-ethinyl estradiol treatment of dysfunctional uterine bleeding cases during adolescence

BACKGROUND

The purpose of this study was to compare the effectiveness of tenoxicam versus lynestrenol-ethinyl estradiol (L-EE) in the treatment of severe cases of dysfunctional uterine bleeding (DUB) during adolescence.

METHODS

Forty-eight patients with objective DUB completed a randomized comparative trial of treatment with tenoxicam (20 mg daily, n = 23) or L-EE (1 tablet containing 0.05 mg + 2.5 mg, respectively, 3 times daily, n = 25). Treatment was given during menorrhagia until bleeding ceased. Mean age of the patients was 13.74 +/- 2.1 years (range, 11-18 years).

RESULTS

A significantly higher level of hematocrit (35.9% v 32.6%, t = 2.1, P = 0.0217) and hemoglobin (11.5 v 10.4 g%, t = 1.7, P = 0.0495), and significantly less hospitalization (5.75 v 8.33 days, t = 2.45, P = 0.0106) was seen in the tenoxicam group in comparison to L-EE group after completion of the treatment. Three patients were submitted to curettage and seven to transfusion in the group receiving L-EE, but no patients in the tenoxicam group required these procedures.

CONCLUSIONS

Tenoxicam is considered an effective medication for the management of DUB during adolescence.

Laminin decreases PRL and IGFBP-1 expression during in vitro decidualization of human endometrial stromal cells

The expression of laminin, a major constituent of endometrial cell basement membranes, is increased during differentiation of human endometrial stromal cells (decidualization). To determine whether laminin plays a role in decidualization, we studied the effects of laminin substrate on the synthesis and release of prolactin (PRL) and insulin-like growth factor binding protein-1 (IGFBP-1), two major secretory proteins of decidualized stromal cells. Endometrial stromal cells were plated on laminin as well as several other extracellular matrix (ECM) proteins (types 1 and IV collagen or fibronectin) and on plastic, and cultured in media containing medroxyprogesterone acetate (MPA) and estradiol. Cells cultured on plastic or ECM proteins displayed similar morphological changes indicative of decidualization. However, the release of PRL and IGFBP-1 from cells cultured on plastic and ECM proteins (types 1 and IV collagen and fibronection) was approximately 2.1-fold and 2.8-fold greater respectively, than from cells cultured on laminin. The decrease in PRL and IGFBP-1 expression in cells cultured on laminin was not due to differences in initial cell attachment efficiency or final DNA content. In addition, laminin had no effect on the content of laminin protein or fibronectin mRNA levels, indicating that the effects of laminin on PRL and IGFBP-1 were specific. PGE2 stimulated the release of PRL and IGFBP-1 from cells cultured on laminin to levels comparable to those from cells cultured on plastic or other ECM proteins. This indicates that the decrease in PRL and IGFBP-1 release by laminin was not due to a generalized unresponsiveness. In contrast to the effects of laminin during decidualization, PRL expression was not altered by laminin in terminally differentiated decidual cells isolated at term. Our results support a role for laminin in selectively regulating PRL and IGFBP-1 gene expression during in vitro decidualization of human endometrial stromal cells.

Prostaglandin deficiency

Healthy cells from virtually all tissues synthesize a variety of prostaglandins, autacoids which can significantly alter cellular functions. An absolute or relative deficiency of prostaglandins has now been demonstrated in many diseases or clinical conditions. These include 'natural' disorders such as peptic ulcer disease and diabetes mellitus. These also include 'acquired' or iatrogenic conditions such as cyclosporine nephrotoxicity and the gastropathy induced by nonsteroidal anti-inflammatory drugs. We believe that the diversity of the disorders associated with prostaglandin deficiency may be wider and of greater pathogenetic importance than is currently recognized. We propose: 1) that prostaglandin deficiency will be demonstrated in many abnormalities which are now described as of uncertain etiology; and 2) that adverse effects from many commonly prescribed drugs may also be related to an unrecognized and unfavorable alteration in prostaglandin synthesis, disposal, or activity.

The effect of dietary supplementation with fish oil fatty acids on surgically induced endometriosis in the rabbit

As a means of assessing the effects of natural inhibition of cyclooxygenase enzymes on arachidonic acid metabolism in vivo, the authors supplemented the diet of 38 New Zealand white rabbits with fish oil containing eicosapentaenoic acid and docosahexaenoic acid (EPA/DHA) or olive oil (control). Endometriosis was surgically induced 10 days later using a previously described experimental technique. Peritoneal fluid PGE2 and PGF2-alpha concentrations were significantly lower in the EPA/DHA group versus controls (P less than 0.05, P = 0.05, respectively). Total endometrial implant diameter 8 weeks after induction of endometriosis was significantly smaller in the experimental group (3.1 +/- 0.2 cm) compared with the controls (4.0 +/- 0.3 cm) (P less than 0.03). The authors conclude that dietary supplementation with fish oil, containing the n-3 polyunsaturated fatty acids EPA and DHA, can decrease intraperitoneal PGE2 and PGF2-alpha production and retard endometriotic implant growth in this animal model of endometriosis.

The role of prostaglandins and allied substances in uterine haemostasis

This review addresses itself to summarizing the more recent studies published on the bioconversion of arachidonic acid in the human endo- and myometrium during the normal menstrual cycle and in women with increased menstrual blood loss. The data indicate an increased ability of the endo- and myometrium from women with menorrhagia to produce prostaglandins with vasodilator and platelet anti-aggregatory properties, viz., prostacyclin and prostaglandin E2. The data on prostaglandin production in endometria of IUD wearers is reviewed and discussed in relation to present knowledge on morphological findings in IUD-influenced endometrium.

Sex steroid and prostaglandin interactions upon the purified rat myometrial plasma membranes

[14C]Estradiol, [14C]estrone, [14C]progesterone and [3H]prostaglandins (PGs) E2 and F2 alpha, when incubated with myometrial plasma membranes (MPM) at a concentration of 1 X 10(-6) M for 1 h at 37 degrees C, bind into MPM at pmolar concentrations. Unlabeled steroids inhibited [3H]PGE2 and [3H]PGF2 alpha binding to MPM in a dose-dependent manner. Membrane-bound and free steroids or PGs were found to be essentially unchanged under the present incubation conditions. Ca2+ ions up to 10 mM increased steroid binding into MPM. Molecular interactions between steroids and MPM were assessed by measuring the steady-state fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH), and by estimating the changes in the allosteric properties of MPM-bound (Na+ + K+)ATPase by fluoride (F-). Steroids appear to increase the MPM fluidity, evaluated through changes in the Hill coefficient for MPM-bound (Na+ + K+)ATPase by F- and by the fluorescence polarization method. Binding of sex steroids to MPM increased the membrane fluidity and decreased the binding of the uterus stimulatory PGs by membrane receptors. These studies provide a basis for postulating that a 'non-genomic' mechanism of sex steroids induces reduction of uterine contractions.

Prostaglandin binding to different cell types of human uterus: quantitative light microscope autoradiographic study

Five human uteri of the menstrual cycle were analyzed by quantitative light microscope autoradiography to determine which uterine cell types contain prostaglandin (PG) binding sites. The results showed that stromal cells, glandular epithelium, elongated and circular smooth muscles, arterioles and erythrocytes in lumen of arterioles contained numerous PGE and very few or no detectable PGF2 alpha binding sites. The grains which were present when incubated with [3H]PGE2 alone completely disappeared following coincubation with excess unlabeled PGE2 but not with excess unlabeled PGA1. Analysis of grain count data revealed that PGE binding sites in arterioles were lower than those in other uterine cell types and PGE binding sites in endometrial cells of proliferative phase uteri were higher than those in secretory phase uteri (P less than 0.05). Thus the present results demonstrate that all the cell types, including arterioles of human uterus of the menstrual cycle, contain PGE and minimal PGF2 alpha binding sites. This suggests that PGE binding sites in different cell types of human uterus subserve diverse effects of PGEs.