A functional study of platelets in menstrual fluid

Menstruation: science and society

Women's health concerns are generally underrepresented in basic and translational research, but reproductive health in particular has been hampered by a lack of understanding of basic uterine and menstrual physiology. Menstrual health is an integral part of overall health because between menarche and menopause, most women menstruate. Yet for tens of millions of women around the world, menstruation regularly and often catastrophically disrupts their physical, mental, and social well-being. Enhancing our understanding of the underlying phenomena involved in menstruation, abnormal uterine bleeding, and other menstruation-related disorders will move us closer to the goal of personalized care. Furthermore, a deeper mechanistic understanding of menstruation-a fast, scarless healing process in healthy individuals-will likely yield insights into a myriad of other diseases involving regulation of vascular function locally and systemically. We also recognize that many women now delay pregnancy and that there is an increasing desire for fertility and uterine preservation. In September 2018, the Gynecologic Health and Disease Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development convened a 2-day meeting, "Menstruation: Science and Society" with an aim to "identify gaps and opportunities in menstruation science and to raise awareness of the need for more research in this field." Experts in fields ranging from the evolutionary role of menstruation to basic endometrial biology (including omic analysis of the endometrium, stem cells and tissue engineering of the endometrium, endometrial microbiome, and abnormal uterine bleeding and fibroids) and translational medicine (imaging and sampling modalities, patient-focused analysis of menstrual disorders including abnormal uterine bleeding, smart technologies or applications and mobile health platforms) to societal challenges in health literacy and dissemination frameworks across different economic and cultural landscapes shared current state-of-the-art and future vision, incorporating the patient voice at the launch of the meeting. Here, we provide an enhanced meeting report with extensive up-to-date (as of submission) context, capturing the spectrum from how the basic processes of menstruation commence in response to progesterone withdrawal, through the role of tissue-resident and circulating stem and progenitor cells in monthly regeneration-and current gaps in knowledge on how dysregulation leads to abnormal uterine bleeding and other menstruation-related disorders such as adenomyosis, endometriosis, and fibroids-to the clinical challenges in diagnostics, treatment, and patient and societal education. We conclude with an overview of how the global agenda concerning menstruation, and specifically menstrual health and hygiene, are gaining momentum, ranging from increasing investment in addressing menstruation-related barriers facing girls in schools in low- to middle-income countries to the more recent "menstrual equity" and "period poverty" movements spreading across high-income countries.

Development of an immunoassay for the differentiation of menstrual blood from peripheral blood

Forensic identification of body fluids is a crucial aspect of the discipline. To date, there are no robust tests to make a distinction between menstrual blood and peripheral blood. Past techniques have fallen short of producing clear and consistent results while present mRNA techniques are still in their infancy. The aim of this study was to develop of an accurate and rapid immunoassay based identification method. Three different targets were evaluated: matrix metalloproteinase 14 (MMP14), oestrogen receptor α (ERα), and fibrinogen. Cellular or membrane bound antigens were analyzed using immunocytochemical staining while soluble antigens were analyzed by indirect ELISA. Results showed that ERα and MMP14 are present in the endometrial cells of menstrual blood but absent in peripheral blood. At a total protein concentration of 10 μg/mL or lower, fibrinogen was detected in menstrual blood but absent in peripheral. If evaluated on a larger scale, immunoassays may prove to be beneficial in discriminating menstruum and peripheral blood.

Effectiveness and acceptability of vitamin E and low-dose aspirin, alone or in combination, on Norplant-induced prolonged bleeding

A study (ISRCTN 77665712) was undertaken to test the effectiveness and the acceptability of vitamin E and low-dose aspirin, alone or in combination, as treatment for prolonged vaginal bleeding induced by Norplant. A total of 486 Norplant users who were requesting treatment for bleeding lasting longer than 7 days were enrolled in five centers: Beijing, China; Jakarta, Indonesia; Santiago, Chile; Santo Domingo, Dominican Republic; and Tunis, Tunisia. They were randomized to one of four different 10-day oral treatments: 200 mg vitamin E daily, 80 mg aspirin daily, both or a placebo. Treatment packs were designed to ensure blinding of both the subjects and the clinical staff. Neither vitamin E nor low-dose aspirin nor their combination was found to have any effect on reducing the length of the bleeding episode for which treatment was taken or on the vaginal bleeding patterns these women experienced during the year of follow-up.

Cyclooxygenase enzymes and prostaglandins in reproductive tract physiology and pathology

Prostaglandins, thromboxanes (TX) and leukotrienes, collectively referred to as eicosanoids, are cyclooxygenase (COX) metabolites of arachidonic acid (AA). Prostaglandins, have been recognised for many years as key molecules in regulating reproductive tract physiology and pathology. Numerous recent studies in in vitro model systems and knockout mouse models have demonstrated specific functional roles for the respective cyclooxygenase enzymes, prostaglandins and prostanoid receptors. Here we review the findings obtained in several of these studies with emphasis on the roles played by cyclooxygenase enzymes and prostaglandins, specifically prostaglandin E2 (PGE2) and F2alpha in reproductive tract physiology and pathology.

Cyclooxygenase-2 overexpression inhibits cathepsin D-mediated cleavage of plasminogen to the potent antiangiogenic factor angiostatin

Overexpression of cyclooxygenase (COX)-2 and enhanced synthesis of prostaglandin E2 (PGE2) have been implicated in human endometrial pathologies. To investigate the molecular role of COX-2, the Ishikawa human endometrial epithelial cell line was stably transfected with the pIRES2 vector containing COX-2 cDNA in either the sense or antisense directions. PGE2 concentrations were significantly elevated in the cells transfected with the COX-2 sense compared with wild-type cells or cells transfected with the antisense cDNA (P < 0.01). Elevated PGE2 synthesis was associated with enhanced expression and signaling of PGE2 receptors (EP). cDNA array analysis revealed differential expression of cathepsin D between the COX-2 sense and antisense cells. Cathepsin D RNA and protein expression was 6.7- and 2.1-fold lower in the COX-2 sense compared with COX-2 antisense cells respectively. Cathepsin D is known to cleave plasminogen to the potent antiangiogenic factor angiostatin. To investigate differential angiostatin generation, conditioned media from COX-2 sense, COX-2 antisense and wild-type cells were incubated with plasminogen and subsequently subjected to Western blot analysis. In comparison to wild-type cells, the cleavage of plasminogen to angiostatin was abolished when incubated in COX-2 sense cells conditioned media and elevated when incubated in COX-2 antisense cells conditioned media. Coincubation of plasminogen with the cathepsin D inhibitor pepstatin A inhibited the cleavage of plasminogen to angiostatin in the COX-2 antisense conditioned media. These data demonstrate that COX-2 exerts a negative feedback on the expression of cathepsin D. This in turn reduces the generation of the antiangiogenic factor angiostatin, hence promoting a proangiogenic environment.

Cyclooxygenase enzymes and prostaglandins in pathology of the endometrium

Prostaglandins are bioactive lipids produced from arachidonic acid by cyclooxygenase (COX) enzymes and specific terminal prostanoid synthase enzymes. After biosynthesis, prostaglandins exert an autocrine-paracrine function by coupling to specific prostanoid G protein-coupled receptors to activate intracellular signalling and gene transcription. For many years, prostaglandins have been recognized as key molecules in reproductive biology by regulating ovulation, endometrial physiology and proliferation of endometrial glands and menstruation. More recently, a role for COX enzymes and prostaglandins has been ascertained in reproductive tract pathology, including carcinomas, menorrhagia, dysmenorrhoea and endometriosis. Although the mechanism by which prostaglandins modulate these pathologies is still unclear, a large body of evidence supports a role for COX enzymes, prostaglandins and prostaglandin receptor signalling pathways in angiogenesis, apoptosis and proliferation, tissue invasion and metastases and immunosuppression. Here, an overview is provided of some of the findings from these studies with specific emphasis on the role of COX enzymes, prostaglandin E(2) and F(2alpha) in disorders of endometrial proliferation and menstruation in non-pregnant women.

Human uterine vascular structures in normal and diseased states

Menstrual bleeding disorders are one of the most common problems presenting to the gynaecologist. There is increasing evidence that alterations in human uterine vascular structures are associated with spontaneous and sex steroid-induced changes in menstrual bleeding patterns. This article will discuss the normal anatomy and physiology of uterine vascular growth, breakdown, and repair and will indicate where altered anatomy and function may contribute to menstrual disorder. In particular, impact of low-dose progestogens on the endometrial vasculature and endometrial vascular fragility will be discussed. Disturbances of myometrial vascular growth and remodeling, including fibroids, adenomyosis, implantation, and arterio-venous malformations will also be addressed.

Clinical implications of disturbances of uterine vascular morphology and function

Menstrual disturbances are one of the most common problems presenting to the gynaecologist. In order for the endometrium to bleed, vessels must break down. Disruption in the regulation of endometrial vascular growth and function has been found in association with spontaneous and sex steroid-induced disturbances of menstrual bleeding. Although circulating oestrogens and progestogens influence the endometrial vessels, this effect appears to be indirect, and regulation is primarily via local factors. Deficient vasoconstriction and haemostasis with excessive fibrinolysis is seen in menorrhagia. Breakthrough bleeding in users of progestogen-only contraceptives is associated with increased superficial vascular fragility and disruptions in the supporting basement membrane. Blood vessels in uterine fibroids are abnormal in distribution and appearance. Adenomyosis is also commonly associated with menstrual disturbance, and alterations in vascular distribution suggest altered angiogenesis. Successful human embryo implantation requires endometrial vascular breakdown. Excessive thrombosis associated with the antiphospholipid syndrome may interfere with this re-modelling and compromise implantation. Arteriovenous malformations are a rare but important cause of excessive or irregular vaginal bleeding. Abundant vessels with abnormal morphology, associated with aberrant angiogenesis can be seen, and embolization of these vessels may be an effective conservative treatment. Improved understanding of the regulation of the uterine vasculature is likely to lead to targeted therapies to prevent unscheduled vascular breakdown and to control menstrual disturbance at an endometrial level.

Evaluation of a menstrual cup to collect shed endometrium for in vitro studies

OBJECTIVE

To evaluate whether a menstrual cup is a suitable instrument to collect antegradely shed endometrium for in vitro studies.

DESIGN

A prospective, descriptive, cell biological and immunohistochemical study.

SETTING

Tertiary care university medical center.

PATIENT(S)

Nine female volunteers with regular cycles.

INTERVENTION(S)

Menstrual effluent was collected with a menstrual cup. Experience with the menstrual cup was described. Cytospin specimens, frozen sections, and cultures were prepared from the obtained menstrual tissue.

MAIN OUTCOME MEASURE(S)

The acceptability of the menstrual cup. The presence and viability of endometrial tissue was evaluated using immunohistochemical staining and culture outcome.

RESULT(S)

All women except one described the menstrual cup as acceptable. Menstrual effluent contained single cells, clumps of cells, and glandlike structures. After 5 days of culture, the endometrial tissue appeared to be viable. Immunohistochemistry showed positive staining for vimentin in most cytospin specimens, in all cryostat specimens, and in 10 of 17 cultures. Cytokeratin 18 stained most cytospin specimens, all cryostat specimens, and 10 of 17 cultures. Positive staining for BW495/36 was observed in most cytospin specimens, all cryostat specimens, and 11 of 17 cultures.

CONCLUSION

A menstrual cup in an acceptable instrument to collect antegradely shed menstrual tissue. Menstruum contains viable endometrial tissue that can be used for in vitro studies of endometrium and endometriosis.

The influence of gender in the evaluation of platelet and plasma catecholamines

The platelet and plasma levels of catecholamines (CA) were simultaneously studied in a group of normal subjects in order to find possible sex-related changes in the distribution of CA in these two compartments. No significant differences between males and females were observed, but a marked platelet noradrenaline increase was found in the luteal phase as compared to the follicular phase. Furthermore, the platelet and plasma CA levels were strongly correlated in the male group but not in the female group. These results, while confirming the existence of a menstrual-related variability in noradrenergic activity, suggest a sex-related difference in the dynamic balance between platelet and plasma CA levels. The simultaneous assay of platelet and plasma CA enabled this phenomenon to be revealed, whereas the separate evaluation of platelet or plasma CA levels would not have done so.

Dysfunctional uterine bleeding

The diagnosis of DUB is made by the exclusion of organic disease as a cause of the abnormal menses; the condition accounts for about 80% of cases of menorrhagia. Of these, over 80% will have no abnormality of the hypothalamo-pituitary-ovarian axis, and it is likely that the disorder is the result of local endometrial factors. There appears to be not only a preponderance of vasodilatory prostaglandins in the endometrium of women with menorrhagia, but also an excessive increase in fibrinolytic activity within the uterine cavity. Once a diagnosis has been reached with the aid of history, examination, haematological and endocrine investigations, and dilatation and curettage when appropriate, medical treatment is the usual first line approach. Non-steroidal anti-inflammatory drugs such as mefenamic acid, or antifibrinolytic agents such as tranexamic or epsilon aminocaproic acids, will reduce blood loss by between 25 and 50%. Though the former drugs are relatively free from side-effects in healthy women, intracranial thrombosis has been reported with the latter (Agnelli et al, 1982). Medications which suppress ovarian function, such as danazol or gonadotrophin releasing hormone analogues, are highly effective in lessening, or inhibiting, menstrual loss, but at the expense of side-effects and convenience respectively. The combined contraceptive pill may reduce blood loss by 50% but is not appropriate for older women. Cyclical gestagens such as norethisterone have been widely employed, particularly for the treatment of anovulatory cycles, but their place in the management of ovulatory DUB is less clear. If medical treatment fails hysterectomy should be considered, though less invasive surgical methods of endometrial ablation are being developed. Finally, it should be remembered that in the absence of associated signs or symptoms of iron-deficiency anaemia, heavy menstrual bleeding is a subjective complaint and up to 50% of women describing menorrhagia will have a measured monthly blood loss within normal limits.