Myometrial Cell Proliferation Research Articles

Hypoxia in uterine fibroids: role in pathobiology and therapeutic opportunities.

Uterine fibroids are the most common tumors in females affecting up to 70% of women world-wide, yet targeted therapeutic options are limited. Oxidative stress has recently surfaced as a key driver of fibroid pathogenesis and provides insights into hypoxia-induced cell transformation, extracellular matrix pathophysiology, hypoxic cell signaling cascades, and uterine biology. Hypoxia drives fibroid tumorigenesis through (1) promoting myometrial stem cell proliferation, (2) causing DNA damage propelling transformation of stem cells to tumor initiating cells, and (3) driving excess extracellular matrix (ECM) production. Common fibroid-associated DNA mutations include MED12 mutations, HMGA2 overexpression, and Fumarate hydratase loss of function. Evidence suggests an interaction between hypoxia signaling and these mutations. Fibroid development and growth are promoted by hypoxia-triggered cell signaling via various pathways including HIF-1, TGFβ, and Wnt/β-catenin. Fibroid-associated hypoxia persists due to antioxidant imbalance, ECM accumulation, and growth beyond adequate vascular supply. Current clinically available fibroid treatments do not take advantage of hypoxia-targeting therapies. Growing pre-clinical and clinical studies identify ROS inhibitors, anti-HIF-1 agents, Wnt/β-catenin inhibition, and TGFβ cascade inhibitors as agents that may reduce fibroid development and growth through targeting hypoxia.

Influence of nutrition on the course of uterine fibroids

Currently, there is a negative trend in the increase in the incidence of uterine fibroids, often diagnosed at a later date, requiring more invasive laparotomic myomectomy, up to hysterectomy. It was also revealed that the patients had an aggravated premorbid background in the form of obesity and related diseases.The purpose of the study. To study domestic and foreign studies. To identify the features of the course of uterine fibroids in patients with hypersthenic and normosthenic body types.Materials and methods. Anonymous and voluntary questionnaire survey with an in-depth collection of food history, interviews of 260 patients and analysis of their case histories with uterine fibroids who underwent laparoscopic and laparotomic myomectomy were carried out, dividing them into 2 groups according to BMI.Results. In both groups, there was the following distribution according to the presence of pregnancies: 0 – 4 % and 5 %, 1 – 86 % and 84 %, 2 – 10 % and 11 % for groups I and II, respectively (p = 0.041 criterion). 25 % in group I and 31 % in group II had a history of surgery – caesarean section. The presence of inflammatory diseases of the pelvic organs in both groups was 89.3 % and 91.6 %, respectively. Also noted was a high consumption of beef and pork by 10 and 23 %, potatoes by 8 % and 13 %, white cabbage by 12 % and 11 %, bakery products by 21 % and 26 %. Low consumption of seafood and fish products by 35 % and 56 %, dairy products by 44 % and 47 %, absolutely low content of olive oil in the daily diet. The above data are presented for groups I and II, respectively. (criterion p = 0.029-0.054).Сonclusions. Obesity plays a role as a risk factor for the development of uterine fibroids, acting either through hormonal or inflammatory mechanisms. Obesity can contribute to the development of insulin resistance and hyperinsulinemia, which can directly or indirectly influence the development of fibroids by promoting the proliferation of myometrial smooth muscle cells and increasing circulating levels of ovarian hormones.

INHIBITION OF BRD PROTEINS SUPPRESSES THE PHENOTYPE OF UTERINE FIBROIDS VIA REGULATION OF N6-METHYLADENOSINE REGULATORS

Bromodomain (BRD)-containing proteins are involved in many biological processes, most notably epigenetic regulation of transcription, and BRD protein dysfunction has been linked to many diseases including tumorigenesis. However, the role of BRD proteins in the pathogenesis of uterine fibroids (UFs), the most common pelvic tumors in women of reproductive age, is unknown. The present study aimed to determine the expression pattern of BRD proteins in UFs and matching myometrium and assess the effect of BRD inhibitors on UF phenotype and epitranscriptomic changes. Human UFs (n=22) and adjacent myometrium tissues (MyoF, n=7) were collected at the time of hysterectomy at the University of Chicago. Western blot (WB) was performed to determine the levels of BRD proteins in UFs and myometrium. Fourteen BRD inhibitors from the Epigenetic Chemical Probe Library provided by the University of Illinois at Chicago were used to determine the cell proliferation by MTT assay. Two BRD inhibitors (I-BRD9 and TP-472) were further used to explore their mechanistic actions. The student’s t-test was used to determine the significant difference. Our studies demonstrated that among 22 UFs analyzed, 96% (21/22, p<0.01), 55% (12/22), 82% (18/22, p<0.01) exhibited the upregulation of BRD2, BRD3, and BRD9 respectively, suggesting the aberrant BRD protein expression may contribute to the pathogenesis of UFs. To examine the biological impact of BRD inhibition on the UFs, 14 BRD inhibitors were screened to identify specific and potent BRD inhibitors in UF cells. 43% (6/14) of these BRD inhibitors selectively inhibited UF, but not myometrial cell proliferation. Furthermore, targeting BRD proteins with BRD inhibitors (I-BRD9 and TP-472) decreased the protein levels of extracellular matrix proteins (Type I Collagen, fibronectin), PCNA (cell proliferation marker), and Bcl-2 (anti-apoptotic marker) in a dose- and time-dependent manner in UF cells. Notably, inhibition of BRD proteins with I-BRD9 and TP-472 downregulated the expression of METTL3, YTHDC2, and YTHDF2, which are the key regulators for N6-methyladenosine (m6A) modification, indicating the tight link between BRD proteins and epitranscriptomic landscape. These results demonstrate for the first time that BRD proteins are aberrantly expressed in UFs. BRD inhibitors suppress the UF phenotype while concomitantly altering the expression of the central m6A regulators.

Vascular biology of uterine fibroids: connecting fibroids and vascular disorders.

Fibroids are benign tumors caused by the proliferation of myometrial smooth muscle cells in the uterus that can lead to symptoms such as abdominal pain, constipation, urinary retention, and infertility. While traditionally thought of as a disease process intrinsic to the uterus, accumulating evidence suggests that fibroid growth may be linked with the systemic vasculature system, although cell-intrinsic factors are certainly of principal importance in their inception. Fibroids are associated with essential hypertension and preeclampsia, as well as atherosclerosis, for reasons that are becoming increasingly elucidated. Factors such as the renin-angiotensin-aldosterone system, estrogen, and endothelial dysfunction all likely play a role in fibroid pathogenesis. In this review, we lay out a framework for reconceptualizing fibroids as a systemic vascular disorder, and discuss how pharmaceutical agents and other interventions targeting the vasculature may aid in the novel treatment of fibroids.

Vilaprisan, a New Selective Progesterone Receptor Modulator in Uterine Fibroid Pharmacotherapy-Will it Really be a Breakthrough?

Vilaprisan (VPR) is a new orally available selective progesterone receptor modulator (SPRM), with anti-proliferative activity against uterine fibroids (UFs). It definitively causes suppression of ovulation and inhibition of proliferation of endometrial, myometrial and UF cells. This review aims to summarize current knowledge on VPR from all studies, including clinical trials, conducted to date and to contextualize the potential role of VPR in future medical regimens for the treatment of UFs. We performed a literature search in PubMed US National Library of Medicine and Google Scholar databases. Both databases were extensively searched for all original and review articles/book chapters as well as congress abstracts published in English until July 2019. The use of VPR for UF therapy was identified by using the keywords: "uterine fibroids" and "vilaprisan". In phase I and II clinical trials, VPR was shown to be effective in ameliorating UF-related clinical symptoms, especially abnormal or excessive uterine bleeding and in shrinking UFs. The tolerability of VPR is roughly similar to that of ulipristal acetate (UPA) and it tends to be more favorable than that of GnRH-agonists. Presently, all trials examining the utility of VPR for the treatment of UF are halted; likely, due to the recently reported cases of hepato-toxicity with UPA, in addition to non reassuring toxicology results from preclinical long-term testing on rodents, carried out in parallel with late stage testing on humans. An accurate summary of robust data related to the safety of VPR is urgently needed to draw definitive conclusions on the future clinical development of this drug for UF therapy.

Quercetin and indole-3-carbinol inhibit extracellular matrix expression in human primary uterine leiomyoma cells.

What is the effect of quercetin and indole-3-carbinol (I3C) on extracellular matrix expression, cell migration and proliferation in human myometrial and uterine leiomyoma cells. Myometrial and leiomyoma cells were treated with quercetin or I3C at different concentrations (10 µg/ml; 50 µg/ml; 100 µg/ml; and 250 µg/ml) for 48 h to measure mRNA and protein expressions of extracellular matrix (collagen 1A1, fibronectin and versican), as well as cell migration and the proliferation rate. Quercetin decreased mRNA levels of collagen 1A1 in myometrial (P < 0.0001) and leiomyoma cells (P < 0.0001). Quercetin reduced mRNA and protein levels of fibronectin in myometrial cells (P < 0.05) and fibronectin protein in leiomyoma cells (P < 0.05). I3C reduced collagen 1A1 mRNA levels in myometrial (P < 0.05) and leiomyoma cells at higher dose (P < 0.05). The protein levels of fibronectin were also reduced in both myometrial and leiomyoma cells with highest dose of I3C (P < 0.05), although mRNA levels were not affected in leiomyoma cells. Neither quercetin nor I3C treatment altered versican mRNA levels in both cell types. A significant reduction of the migration of both myometrial and leiomyoma cells in response to quercetin was observed (P < 0.05) and I3C (P < 0.05 for myometrial and P < 0.01 for leiomyoma cells) treatment. Both quercetin and I3C significantly reduced myometrial cell proliferation (P < 0.05). The in-vitro anti-fibrotic, anti-migratory and anti-proliferative effects of quercetin and I3C form the scientific basis for developing new therapeutic, preventive agents, or both, for uterine leiomyomas.

P1704 An unusual mass in the right heart

Abstract A 39 year old patient after removal of the uterus, the left oviduct and the right appendages due to Tu (massive fibroids). The histopathological examination revealed: leiomyomatosis intravascularis masiva (multifocal, intravenous smooth muscle cell hyperplasia without necrosis, cellular atypia and mitotic activity. Vascular invasion within the uterus, parametrium, mesovarium, perinodule tissues). The patient was admitted to the Gynaecology Clinic on the 9th postoperative day due to pain in the right lumbar region. The angio-CT of the thoracic, abdominal and pelvic cavities revealed a tumour/thrombus in the right internal iliac vein, common iliac vein and inferior vena cava (VCI). Then, the patient underwent transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE) revealing an additional mass in the VCI entering the right atrium (RA), periodically passing through the tricuspid valve to the right ventricle (RV). The mass was of irregular shape, free-floating and did not obstruct the right ventricle inflow. Due to a suspicion of thrombus, an attempt at pharmacological treatment was initiated: initially LMWH at a therapeutic dose, followed by UFH iv. (controlled by APTT). Follow-up echocardiography: the image has not changed, the mass is still in the same location. The patient then underwent a surgical treatment: the pathological mass with a length of 35 cm was removed from VCI and RA with extracorporeal circulation. The histopathological examination confirmed: numerous foci of intravenous leiomyomatosis in the form of smooth muscle hyperplasia penetrating into the light of numerous vessels, mainly venous. Discussion Uterine fibroids are the most common benign tumours of the reproductive tract in premenopausal women, they are also the most common cause of hysterectomy. They are formed as a result of benign proliferation of myometrial smooth muscle cells. A special, though very rare, form is intravenous leiomyomatosis (IVL) - caused by abnormal growth of benign tumours, arising from smooth muscle, into venous vessels. Although histopathologically they are benign tumours, due to the possible invasion of large vessels they can be highly "aggressive" and extend into the heart chambers and pulmonary arteries (intracardiac leiomyomatosis - ICLM). Possible symptoms of ICLM: dyspnoea (30-37%), peripheral oedema (20-28%), chest pain (12-30%), palpitation (10-17%), fainting (11%). Approximately 13% of patients have no symptoms at all. In the differential diagnosis of masses in the right heart cavities, the following should be taken into account : thrombus, myxoma, metastases of malignant neoplasms, in particular renal cancer, as well as: liver cancer, adrenal cancer, lymphoma, leiomyosarcoma. Conclusion IVL should be taken into account as a differential diagnosis in case of a free-floating mass in the right heart chambers, originating from the inferior vena cava, among premenopausal women with a history of hysterectomy. Abstract P1704 Figure. mass in the right atrium

Adlay (Coix lachryma-jobi L. var. ma-yuen Stapf.) Hull Extract and Active Compounds Inhibit Proliferation of Primary Human Leiomyoma Cells and Protect against Sexual Hormone-Induced Mice Smooth Muscle Hyperproliferation.

Uterine leiomyomas, also known as fibroids, are benign neoplasms of the uterus and have a high incidence rate in women of reproductive age. Hysterectomy or myomectomy is the initial treatment, but fibroids will recur if the patient is still exposed to similar risk factors. Therefore, developing new therapeutic strategies are urgently necessary. In this study, the anti-proliferation effects of each fraction of adlay seeds were evaluated in uterine leiomyomas, and we identified the potential phytochemical compounds. We found that the ethyl acetate fraction of adlay hull (AHE-ea) appeared to be highly efficient in the anti-proliferation of rat uterine leiomyoma ELT3 cells and primary human uterine leiomyoma (hUL) cells. The proliferation of primary human normal uterine smooth muscle (UtSMC) and normal uterine myometrial (hUM) cells were also suppressed by AHE-ea. Two phytosterols, stigmasterol and β-sitosterol, were identified from AHE-ea fraction. Mice treated with AHE-ea and stigmasterol alone demonstrated reduced diethylstilbestrol/medroxyprogesterone 17-acetate (DES/MPA)-induced uterine myometrial hyperplasia, which is the critical step for the development of leiomyoma. Taken together, our results suggest that the AHE-ea fraction could be considered as a natural plant-based medicine in the prevention or treatment of uterine leiomyoma growth.

Seipin deficiency leads to defective parturition in mice.

Seipin is an integral endoplasmic reticulum membrane protein encoded by Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2/Bscl2) gene. Seipin deficiency results in lipodystrophy, diabetes, muscle hypertrophy, and male infertility in both human and mouse. Seipin function in female reproduction is unknown. Bscl2-/- dams had normal embryo implantation and body weight gain during pregnancy but reduced delivery rates from 2nd to 4th pregnancies and reduced numbers of pups delivered from 1st to 4th pregnancies. Characterization of first pregnancy revealed increased gestation period and parturition problems, including uterine prolapse, difficulty in delivery, undelivered fetuses, and undelivered tissues in Bscl2-/- females. Bscl2-/- uterine weight was comparable to control at 3 weeks old but significantly increased with myometrial hypertrophy at 10 months old. In situ hybridization revealed relatively low level of Bscl2 mRNA expression in myometrium throughout pregnancy and postpartum but high level of expression in uterine luminal epithelium, suggesting that systemic effect (e.g. elevated glucose and insulin levels) rather than local seipin-deficiency in myometrium might be a main contributing factor to myometrial hypertrophy. On near-term gestation day 18.5 (D18.5), Bscl2-/- females had normal levels of serum progesterone and 17β-estradiol, indicating functional ovary and placenta. Proliferating Cell Nuclear Antigen (PCNA) staining showed minimal myometrial cell proliferation in both D18.5 Bscl2+/+ and Bscl2-/- uteri. There was strong LC3 immunostaining in Bscl2+/+ and Bscl2-/- peripartum myometrium and increased LC3 staining in Bscl2-/- peripartum uterine luminal epithelium, suggesting a potential role of seipin in regulating autophagy in uterine luminal epithelium but not myometrium. This study demonstrates an association of seipin with myometrium and parturition.

Resveratrol inhibits proliferation of myometrial and leiomyoma cells and decreases extracellular matrix-associated protein expression

Uterine fibroids (leiomyomas) are the most common benign tumours in women during their reproductive age. Hyperplasia of uterine smooth muscle cells and abnormal deposition of extracellular matrix (ECM) are responsible for the development of uterine fibroids. Studies have shown that food rich in phytochemicals can prevent or treat leiomyoma. Therefore, the purpose of this study is to demonstrate the inhibitory effects of resveratrol on uterine fibroid cell growth and ECM-associated protein expression. We found that resveratrol inhibited the proliferation of leiomyoma cell line (ELT3) and uterine smooth muscle cell line (UtSMC) and affected the cell morphology of both cell lines, induced cell cycle arrest at S and G2/M phase, regulated cell apoptosis associated protein expression and induced cell apoptosis, and affected ECM-associated mRNA and protein expression. Our results suggest that resveratrol is potentially effective in preventing the hyperplasia of leiomyoma and uterine smooth muscle cells.

In Vivo Evidence of the Androgen Receptor in Association With Myometrial Cell Proliferation and Apoptosis.

The androgen receptor (AR) plays essential roles in female reproductive physiology. In vitro studies have shown that AR exerts 2 distinct but related functions in myometrial cells. The AR is required for myometrial cell cycling ligand independently, thereby controls myometrial cell proliferation. The AR also exerts antiapoptotic functions through myeloid cell leukemia 1 (MCL1) in both ligand-dependent and ligand-independent manners. However, these AR functions have not yet been confirmed in vivo. This study provides in vivo evidence that AR expression is associated with myometrial cell proliferation and apoptosis. Myometrial tissue was collected on day 6 of pregnancy from mice bearing an intact AR (AR+/+) or mice with AR heterozygous (AR-/+) or homozygous (AR-/-) functional knockout. Human uterine leiomyoma and paired myometrial tissue biopsies (n = 14 patients) were collected during hysterectomy. Immunohistochemistry was used to assess the protein expression of AR, MCL1, and Ki-67 index, as well as the functional associations of AR with MCL1 and Ki-67 index. In AR-/- mice, MCL1 protein levels were reduced ∼50% in both circular and longitudinal myometrial cells when compared with that in AR+/+ and AR-/+ mice. By contrast, Ki-67 index remained unchanged. The AR protein expression and Ki-67 index in leiomyoma were ∼2- to 3-fold higher than that in normal myometrium. Although MCL1 expression was not coordinately increased in leiomyoma, strong positive correlations between AR and MCL1 expression were observed in leiomyoma but not in normal myometrium tissue. These results suggest that AR is an important regulator of myometrial growth in vivo during pregnancy and in leiomyoma.

Raf Kinase Inhibitor Protein (RKIP) expression and function in human myometrium and leiomyoma

Many growth factors been identified in human myometrium and leiomyoma and activate multiple signaling pathways in order to regulate major cellular processes, including proliferation and fibrosis which are linked to uterine leiomyoma development and growth. The Raf kinase inhibitor protein (RKIP) has emerging roles as regulator of multiple signaling networks including mitogen activated protein (MAP) kinase cascade, as well as interaction with glycogen synthase kinase 3 (GSK3). In our study, we aimed to investigate the presence of RKIP in human myometrium and leiomyoma as well as to determine the effect of locostatin (RKIP inhibitor) on extracellular matrix (ECM) production, proliferation and migration in human myometrial and leiomyoma cells. Myometrial and leiomyoma tissues were used to investigate the localization and the expression level of RKIP through immunohistochemistry and western blotting. Myometrial and leiomyoma cells were treated with locostatin to measure ECM expression by real time PCR, GSK3b expression by western blotting, cell migration by wound-healing assay and cell proliferation by MTT assay. We found that RKIP is expressed in human myometrial and leiomyoma tissue. Locostatin treatment resulted in the activation of the MAPK signal pathway (ERK phosphorylation), providing a powerful validation of our targeting protocol. Further, RKIP inhibition by locostatin reduces ECM components. Moreover, the inhibition of RKIP by locostatin impaired cell proliferation and migration in both leiomyoma and myometrial cells. Finally, locostatin treatment reduced GSK3β expression. Therefore, even if the activation of MAPK pathway should increase proliferation and migration, the destabilization of GSK3β leads to the reduction of proliferation and migration of myometrial and leiomyoma cells.

Dose-dependent biphasic leptin-induced proliferation is caused by non-specific IL-6/NF-κB pathway activation in human myometrial cells.

Leptin, an adipokine synthesized by the placenta during pregnancy, has been proposed for the management of preterm labour (PTL), as it is able to prevent in vitro uterine contractility and remodelling associated with labour onset. Another common feature of labour onset is the phenotypic switch of myometrial smooth muscle cells from a proliferative to a hypertrophic state. As proliferative effects have been demonstrated for leptin in other tissues, we aimed to investigate its ability to induce myometrial proliferation and thus to maintain uterine quiescence. We stimulated human primary myometrial smooth muscle cells with leptin in the presence or absence of receptor antagonists or signalling pathway inhibitors. Leptin induced myometrial cell proliferation in a biphasic manner. At 6.25 ng · mL(-1), leptin-induced proliferation was mediated by the leptin receptor and required the early activation of ERK1/2. At a concentration above 25 ng · mL(-1), leptin induced direct non-specific stimulation of the IL-6 receptor, leading to NF-κB activation, and exerted anti-proliferative effects. However, at 50 ng · mL(-1), leptin re-induces proliferation via IL-6 receptor stimulation that requires STAT3 and delayed ERK1/2 activation. These data bring new insights into leptin signalling-induced myometrial proliferation and its interrelationship with the IL-6/IL-6 receptor axis. In the light of our previous work, the present study emphasizes the potential value of leptin in the pharmacological management of PTL and it also strengthens the hypothesis that leptin might be a contributory factor in the parturition-related disorders observed in obese women.

The androgen receptor mediates antiapoptotic function in myometrial cells

During pregnancy, myometrial phenotype is programmed into three characteristic stages referred to as the early proliferative, the midterm hypertrophic, and the late contractile stage. Increased myometrial growth in the early and midterm of pregnancy involves a complex process of cell proliferation, antiapoptosis and differentiation. We have previously demonstrated that the androgen receptor (AR) is required for myometrial cell proliferation by modulating IGF-1 signaling during early pregnancy. Here, we report that AR also exerts its antiapoptotic function in human myometrial cells. Enhanced AR expression protects, whereas AR silencing sensitizes myometrial cells to both intrinsic and extrinsic apoptotic stimuli. AR agonist inhibits, whereas AR antagonist induces myometrial cells to undergo apoptotic cell death. Gene microarray analysis confirms that the central functions of AR in myometrial cells are to regulate cell cycling and apoptosis through three major gene groups involving the epidermal growth factor (EGF) signaling, RNA splicing and DNA repair processes. AR mediates its antiapoptotic function through two distinct pathways. In the receptor-dependent pathway, AR is required for the expression of several protein factors within the EGF signaling pathway. Through the PI3K/Akt pathway, AR enhances the expression of the antiapoptotic protein Mcl-1. In the ligand-dependent pathway, AR agonist triggers the activation of Src kinase, which in turn phosphorylates STAT3 to increase Mcl-1 expression. We conclude from these results that the AR signaling exerts antiapoptotic function in myometrial cells, further supporting its key role in programming of myometrial phenotype.

Insulin resistance and uterine fibroids: is there an association and does this vary across race/ethnic groups?

Insulin and IGF-1 have been hypothesized to play a role in fibroid pathogenesis through direct promotion of myometrial cell proliferation or by increasing circulating ovarian hormone levels. Compared to White women, Black women have higher levels of insulin resistance (IR) and are also disproportionately affected by fibroids even when normal-weight adults are compared. Our goal was to characterize the relationship between markers of IR and IGF-1, and prevalence of fibroids, in a multi-ethnic population.

Current Perspectives in Uterine Research: Reviews From the Society for Gynecologic Investigation Myometrium and Parturition Satellite Symposia

It is difficult to imagine examples of greater physiological adaptations than those of the uteroplacental unit during pregnancy. The sheer scale of molecular, cellular and tissue remodeling, organogenesis, and organism development in a relatively short period of time seems the epitome of ‘‘systems biology.’’ The processes are challenging to comprehend, and investigate experimentally, but undoubtedly fascinating. Efforts to understand the physiology and pathology of these phenomena are of prime importance due to the considerable health and socioeconomic pressures brought to bear by the high incidences of compromised pregnancies and, especially, preterm birth (PTB). The World Health Organization-sponsored studies equate the worldwide incidence of PTB to be approximately 13 million births per year with approximately 1 million neonatal deaths attributable to PTB. If improved diagnosis and therapeutic treatment of PTB are to be achieved, an integrated understanding of the physiological basis of pregnancy and parturition is required. With this in mind, each year the Myometrium and Parturition Satellite Symposium of the Society for Gynecologic Investigation meeting gathers international experts in this field to share their experimental findings. We are delighted that several plenary speakers from the 2011 and 2012 symposia have provided reviews on their topics for this issue of Reproductive Sciences. The articles provide an up-to-date compendium that integrates many of the important facets of uteroplacental remodeling and function leading to term and preterm labor. Jerome Strauss (Virginia) introduces the importance of dynamic remodeling of the extracellular matrix (ECM) and its molecular components in uteroplacental tissues. With a focus on fetal membrane interfaces, he summarizes the ECMs’ multiplicity of roles including receptor signaling, cytokine/ growth factor sequestration, and tensile strength. Among the important molecular components are fetal fibronectin, hyaluronan, and up to 28 collagens, regulated by different metallomatrix proteinases. Mutations in many genes encoding such ECM proteins are associated with increased incidence of preterm premature rupture of membranes and the roles of environmental and/or epigenetic factors are being increasingly elucidated. In a similar vein, Shynlova et al (Toronto, Canada) describe pregnancy in terms of progressive changes of tissue remodeling under the control of localized inflammatory events (physiological inflammation). The authors posit a carefully structured theory whereby spatially restricted inflammatory events are under the influence of ever-changing endocrine (and a focus is given to the role of progesterone) and mechanical inputs activating a rich milieu of chemokine/cytokine signaling. These, in turn, serve to coordinate diverse processes such as decidualization, myometrial cell proliferation and growth, leukocyte migration, cervical remodeling, and postparturient involution. Olcese et al (Tallahassee, USA) review an oft-neglected consideration of the mechanisms responsible for the timing of parturition. They too give credence to the notion that pregnancy and parturition involve dynamic physiological adaptations—in this case that uterine contractions of labor may be initiated by activity of the central circadian oscillator of the maternal hypothalamic suprachiasmatic nuclei via the feedback ‘‘gating’’ actions of neuroendocrine outputs. Of key importance may well be circadian secretion of melatonin given recent interest in the uterotonic actions of this hormone and uterine expression of melatonin receptors. Regulation of contractile activity of the uterus is also the focus of reviews by Europe-Finner et al (Newcastle, UK) and Wim Lammers (Al Ain, UAE). The former concentrates on intracellular signaling and describes the possibility that posttranslational modification by acetylation may be a mechanism of wider significance to the uterus than first realized when considering ‘‘‘only’’ nuclear events of histone modification, chromatin remodeling, and gene transcription. They suggest

TGF beta family members function in uterine healthy and fibrotic smooth muscle cells

Uterine leiomyomas are the most common benign tumors of fertile women and the most common indication for hysterectomy. Despite the high prevalence, significant health problems, and huge economical impact on the healthcare system, relatively little is understood about the etiology and pathophysiology of uterine leiomyoma (1). Consequently, medical treatments are still limited (2). The role of the growth factors as ultimate mediators of the steroids hormone is evident in the modulation of the cell proliferation and the morphological cells appearance (3). Activin-A and myostatin are growth factors belonging to TGF-β super family expressed and acting in myometrial (4,5) and leiomyoma cells (6) We aimed to explore the functions of activin and myostatin in human myometrial and leiomyoma cells. First we tested both Smad and non-Smad signaling pathways by western blot. We found that activin-A and myostatin can activate only Smad signaling pathway in both myometrial and leiomyoma cells. Next we explored the effect on cell proliferation and on fibrotic phenotype. We found that activin-A and myostatin are able to suppress primary myometrial cell proliferation but they cannot alter the proliferation of leiomyoma cells. In the next step, we found that activin-A can significantly increase fibronectin expression in leiomyoma cells. Those above results suggest that activin-A and myostatin may express antiproliferative and/or fibrotic effects depending on the cell types by activating Smad signaling pathway.

Effect of manganese exposure on the reproductive organs in immature female rats.

Manganese (Mn2+) is a trace element that is essential for normal physiology, and is predominantly obtained from food. Several lines of evidence, however, demonstrated that overexposure to MnCl2 exerts serious neurotoxicity, immunotoxicity and developmental toxicity, particularly in male. The present study aimed to evaluate the effect of 0, 1.0, 3.3, and 10 mg/kg/day doses of MnCl2 on the reproductive organs in the immature female rats. Rats (PND 22; S.D. strain) were exposed to MnCl2 (MnCl2 ∙ 4H2O) dissolved in drinking water for 2 weeks. The animals were sacrificed on PND 35, then the tissues were immediately removed and weighed. Histological studies were performed using the uteri tissue samples. Serum LH and FSH levels were measured with the specific ELISA kits. Body weights of the experimental group animals were not significantly different from those of control group animals. However, ovarian tissue weights in 1 mg and 3.3 mg MnCl2 dose groups were significantly lower than those of control animals (p<0.05 and p<0.01, respectively). Uterine tissue weights of 3.3 mg dose MnCl2 groups were significantly lower than those of control animals (p<0.01), while the 1 mg MnCl2 dose and 10 mg MnCl2 dose failed to induce any change in uterine weight. Similarly, only 3.3 mg MnCl2 dose could induce the significant decrease in the oviduct weight compared to the control group (p<0.05). Non-reproductive tissues such as adrenal and kidney failed to respond to all doses of MnCl2 exposure. The uterine histology revealed that the MnCl2 exposure could affect the myometrial cell proliferation particularly in 3.3 mg dose and 10mg dose group. Serum FSH levels were significantly decreased in 1mg MnCl2 dose and 10 MnCl2 mg groups (p<0.05 and p<0.01, respectively). In contrast, treatment with 1 mg MnCl2 dose induced a significant increment of serum LH level (p<0.05). The present study demonstrated that MnCl2 exposure is capable of inducing abnormal development of reproductive tissues, at least to some extent, and altered gonadotropin secretions in immature female rats. Combined with the well-defined actions of this metal on GnRH and prolactin secretion, one can suggest the Mn2+ might be a potential environmental mediator which is involved in the female pubertal process.

Effects of hormonally active agents on steroid hormone receptor expression and cell proliferation in the myometrium of ovariectomized macaques.

Hormone replacement therapy and selective estrogen receptor modulators have been controversial treatment options for postmenopausal women because of their potential health benefits and/or risks. In this study, we determine the effects of the hormonally active compounds, conjugated equine estrogens (CEE), medroxyprogesterone acetate (MPA), CEE + MPA, and tamoxifen (TAM) on the myometrium of ovariectomized macaques. Immunoexpression of estrogen receptor-α (ERα), progesterone receptor (PR), and Ki-67 in the myometrium is assessed. We found no significant difference in ERα myometrial expression in the CEE, MPA, and CEE + MPA treatment groups, but there was a significant decrease in expression in animals administered TAM versus controls. Conjugated equine estrogen-, TAM-, and CEE + MPA-treated animals had significantly increased expression of PR in myometrial cells and there was no difference in PR expression in cells from MPA-treated animals versus control animals. Myometrial cell proliferation did not significantly differ between the controls and any of the treatment groups, although normalized Ki-67 values were somewhat higher in the CEE and TAM groups. These data suggest that ERα and PR expression in the myometrium is influenced by treatment with hormonally active agents.

Vitamin D receptor (VDR) is over-expressed in the center of uterine fibroids

OBJECTIVE: Bioactive Vit D is anti-proliferative. It blocks the cell-cycle at G1/S, blocks mitogenic signaling of estrogen, EGF and IGF-1, and up-regulates TGFß, a modulator of fibrosis. Bioactive Vit D also activates VDR-mediated apoptosis. This vitamin has recently been associated with fibroids and has been reported to inhibit myometrial (M) and fibroid (F) cell proliferation in vitro. Our goal was to determine the expression of VDR in uterine fibroids.