Association between maternal cigarette smoking cessation and risk of preterm birth in Western New York

BACKGROUND

Although many studies suggested the benefit of smoking cessation among pregnant women in reducing the risk of preterm birth (PTB), the timing of the effect of the cessation remains inconclusive.

OBJECTIVES

To examine the association of trimester-specific smoking cessation behaviours with PTB risk.

METHODS

We included 199,453 live births in Western New York between 2004 and 2018. Based on self-reported cigarette smoking during preconception and in each trimester, we created six mutually exclusive groups: non-smokers, quitters in each trimester, those who smoked throughout pregnancy, and inconsistent smokers. Risk ratios (RRs) and 95% confidence intervals (CIs) were estimated using Poisson regression to examine the association between smoking cessation and PTB. Effect modification by illegal drug use, maternal age, race and ethnicity and pre-pregnancy body mass index (BMI) was investigated multiplicatively by ratio of relative risk and additively by relative excess risk due to interaction (RERI).

RESULTS

Overall, 6.7% of women had a PTB; 14.1% smoked throughout pregnancy and 3.4%, 1.8% and 0.8% reported quitting smoking during the first, second and third trimesters, respectively. Compared to non-smokers, third-trimester cessation (RR 1.20, 95% CI 1.01, 1.43) and smoking throughout pregnancy (RR 1.27, 95% CI 1.21, 1.33) were associated with a higher PTB risk, while quitting smoking during the first or second trimester, or inconsistent smoking was not associated with PTB. A positive additive interaction was identified for maternal age and late smoking cessation or smoking throughout pregnancy on PTB risk (RERI 0.17, 95% CI 0.00, 0.36), and a negative interaction was observed for pre-pregnancy BMI ≥30 kg/m2 (ratio of relative risk 0.70, 95% CI 0.63, 0.78; RERI -0.42, 95% CI -0.56, -0.30).

CONCLUSION

Compared to non-smokers, smoking throughout pregnancy and third-trimester smoking cessation are associated with an increased risk of PTB, while quitting before the third trimester may not increase PTB risk.

TNFα-Induced Altered miRNA Expression Links to NF-κB Signaling Pathway in Endometriosis

Endometriosis is a common gynecological inflammatory disorder characterized by immune system dysregulation, which is involved in lesion initiation and progression. Studies have demonstrated that several cytokines are associated with the evolution of endometriosis, including tumor necrosis factor-α (TNFα). TNFα is a non-glycosylated cytokine protein with potent inflammatory, cytotoxic, and angiogenic potential. In the current study, we examined the ability of TNFα to induce dysregulation of microRNAs (miRNAs) linked to NFkB signaling pathways, thus contributing to the pathogenesis of endometriosis. Using RT-qPCR, the expression of several miRNAs was quantified in primary cells derived from eutopic endometrium of endometriosis subjects (EESC) and normal endometrial stromal cells (NESC), and also TNFα-treated NESCs. The phosphorylation of the pro-inflammatory molecule NF-κB and the candidates of the survival pathways PI3K, AKT, and ERK was measured by western blot analysis. The elevated secretion of TNFα in EESCs downregulates the expression level of several miRNAs significantly in EESCs compared to NESCs. Also, treatment of NESCs with exogenous TNFα significantly reduced the expression of miRNAs in a dose-dependent manner to levels similar to EESCs. In addition, TNFα significantly increased the phosphorylation of the PI3K, AKT, ERK, and NF-κB signaling pathways. Notably, treatment with curcumin (CUR, diferuloylmethane), an anti-inflammatory polyphenol, significantly increased the expression of dysregulated miRNAs in EESC in a dose-dependent manner. Our findings demonstrate that TNFα is upregulated in EESCs, which subsequently dysregulates the expression of miRNAs, contributing to the pathophysiology of endometriotic cells. CUR effectively inhibits the expression of TNFα, subsequently altering miRNA levels and suppressing the phosphorylation of AKT, ERK, and NF-κB.

Neurotrophins and Their Receptors, Novel Therapeutic Targets for Pelvic Pain in Endometriosis, Are Coordinately Regulated by IL-1β via the JNK Signaling Pathway

Pelvic pain in women with endometriosis is attributed to neuroinflammation and afferent nociceptor nerves in ectopic and eutopic endometrium. The hypothesis that uterine nociception is activated by IL-1β, a prominent cytokine in endometriosis, was tested herein. Immunofluorescence histochemistry confirmed the presence of neurons in human endometrial tissue. Expression of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) and their receptors in endometrial tissue and cells was validated by immunohistochemistry and Western blotting. Isolated endometrial stromal cells (ESCs) were subjected to dose-response and time-course experiments with IL-1β and kinase inhibitors to characterize in vitro biomarkers. Neural biomarkers were co-localized in endometrial nerve fibers. NGF, BDNF, and their receptors tropomyosin receptor kinase (Trk) A, TrkB, and p75 neurotrophin receptor were all expressed in primary ESCs. IL-1β stimulated higher TrkA/B expression in ESCs derived from endometriosis cases (2.8- ± 0.2-fold) than cells from controls (1.5- ± 0.3-fold, t-test, P < 0.01), effects that were mediated via the c-Jun N-terminal kinase (JNK) pathway. BDNF concentrations trended higher in peritoneal fluid of endometriosis cases but were not statistically different from controls (P = 0.16). The results support the hypothesis that NGF and BDNF and their corresponding receptors orchestrate innervation of the endometrium, which is augmented by IL-1β. We postulate that JNK inhibitors, such as SP600125, have the potential to reduce neuroinflammation in women with endometriosis.

TNFα-induced altered miRNA expression links to NF-κB signaling pathway in endometriosis

Endometriosis is a common gynecological inflammatory disorder characterized by immune system dysregulation, which is involved in lesion initiation and progression. Studies have demonstrated that several cytokines are associated with the evolution of endometriosis, including tumor necrosis factor-α (TNFα). TNFα is a non-glycosylated cytokine protein with potent inflammatory, cytotoxic, and angiogenic potential. In the current study, we examined the ability of TNFα to induce dysregulation of microRNAs (miRNAs) linked to NFkB-signaling pathways, thus contributing to the pathogenesis of endometriosis. Using RT-QPCR, the expression of several miRNAs were quantified in primary cells derived from eutopic endometrium of endometriosis subjects (EESC) and normal endometrial stromal cells (NESC) and also TNFα treated NESCs. The phosphorylation of the pro-inflammatory molecule NF-κB and the candidates of the survival pathways PI3K, AKT and ERK was measured by westernblot analysis. The elevated secretion of TNFα in EESCs downregulates the expression level of several miRNAs significantly (p < 0.05) in EESCs compared to NESC. Also treatment of NESCs with exogenous TNFα significantly reduced the expression of miRNAs in a dose-dependent manner to levels similar to EESCs. In addition, TNFα significantly increased the phosphorylation of the PI3K, AKT, ERK, and NF-κB signaling pathways. Notably, treatment with curcumin (CUR, diferuloylmethane), an anti-inflammatory polyphenol, significantly increased the expression of dysregulated miRNAs in EESC in a dose-dependent manner. Our findings demonstrate that TNFα is upregulated in EESCs, which subsequently dysregulates the expression of miRNAs, contributing to the pathophysiology of endometriotic cells. CUR effectively inhibits the expression of TNFα, subsequently altering miRNA levels and suppresses the phosphorylation of AKT, ERK, and NF-κB.

Testing of drugs using human feto-maternal interface organ-on-chips provide insights into pharmacokinetics and efficacy

Objectives: To improve preclinical drug testing during pregnancy, we developed multiple microfluidic organ-on-chip (OOC) devices that represent the structure, functions, and responses of the two feto-maternal interfaces (FMis) in humans (fetal membrane [FMi-OOC] and placenta [PLA-OOC]). This study utilized feto-maternal interface OOCs to test the kinetics and efficacy of drugs during pregnancy. Study design: The FMi-OOC contained amnion epithelial, mesenchymal, chorion trophoblast, and decidual cells. The PLA-OOC contained cytotrophoblasts (BeWo), syncytiotrophoblasts (BeWo + forskolin), and human umbilical vein endothelial cell lines. Therapeutic concentrations of either pravastatin or rosuvastatin (200 ng mL^-1), a model drug for these experiments, were applied to either decidua (in FMi-OOC) and syncytiotrophoblasts (in PLA-OOC) chambers under normal and oxidative stress conditions (induced by cigarette smoke extract [CSE 1 : 25]) to evaluate maternal drug exposure during normal pregnancy or oxidative stress (OS) associated pathologies, respectively. We determined statin pharmacokinetics and metabolism (LC-MS/MS), drug-induced cytotoxicity (LDH assay), and efficacy to reduce OS-induced inflammation (multiplex cytokine assay). Results: Both OOCs mimicked two distinct human feto-maternal interfaces. The drugs tested permeated the maternal-fetal cell layers of the FMi-OOC and PLA-OOC within 4 hours and generated cell and time-specific statin metabolites from various cell types without causing any cytotoxicity. OS-induced pro-inflammatory cytokines were effectively reduced by statins by increasing anti-inflammatory cytokine response across the FMi-OOC and PLA-OOC. Conclusion: Two distinct feto-maternal interface OOCs were developed, tested, and validated for their utility to conduct preclinical trials during pregnancy. We demonstrated that the placenta and fetal membranes-decidual interface both are able to transport and metabolize drugs and that the safety and efficacy of a drug can be determined using the anatomical structures recreated on OOCs.

RF34 | PMON229 TNFa-Induced Altered miRNA Expression Links to Inflammation in Endometriosis

Endometriosis is a common gynecological inflammatory disorder, which is characterized by immune system dysregulation with initiation and progression. It affects 5% to 15% of reproductive-age women and is present in as many as 30% to 50% of patients with infertility and/or pain. In previous studies, including ours, have demonstrated that several cytokines have been associated with the evolution of endometriosis, including tumor necrosis factor-a (TNFa). TNFa is a non-glycosylated protein which has potent inflammatory, cytotoxic, and angiogenic potential. Therefore, in the current studies, we examined the effects of TNFa over a time course in the regulation of proinflammatory and proangiogenic microRNAs (miRNAs) in primary cultures of normal endometrial stromal cells (NESC) and compared with the untreated cells derived from eutopic endometrium of endometriosis subjects (EESC). miRNAs are short, 18- to 22-nucleotide– size, non-coding RNAs that act as post-transcriptional modulators of gene expression and are involved in the pathogenesis of endometriosis. Using NanoString nCounter-based assays and quantitative RT-PCR, we have identified levels of several proinflammatory and proangiogenic miRNAs higher in EESC than NESC. NESC treatment with TNFa significantly altered the expression of proinflammatory and proangiogenic miRNAs in a time-dependent manner. Notably, TNFa significantly decreased phosphorylation of the PI3K, AKT, and ERK signaling pathways. Moreover, treatment of EESC and NESC with curcumin (diferuloylmethane, CUR), an anti-inflammatory folk medicine in Asian countries, significantly increased the expression of anti-inflammatory and anti-angiogenic miRNAs in a dose- and time-dependent manner. These findings demonstrate higher inflammatory, and proangiogenic miRNA production in EESC may be due to a higher concentration of TNFa than NESC under basal conditions. Therefore, suppressing TNFa may reduce the inflammatory and angiogenic miRNA associated with endometriosis.

Sources of Research Support: This study was supported in part by National Institutes of Health Grants 1SC3 GM113751, U01, 1SC1 GM130544, HD66439, 1R01HD057235, U54 CA118948, HD41749, S21MD000101 and G12-MD007602. This investigation was conducted in a facility constructed with support from Research Facilities Improvement Grant #C06 RR018386 from NIH/NCRR.

Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m., Monday, June 13, 2022 1:06 p.m. - 1:11 p.m.

ENDOCELL-Seud: a Delphi protocol to harmonise methods in endometrial cell culturing

In vitro

culturing of endometrial cells obtained from the uterine mucosa or ectopic sites is used to study molecular and cellular signalling relevant to physiologic and pathologic reproductive conditions. However, the lack of consensus on standard operating procedures for deriving, characterising and maintaining primary cells in two- or three-dimensional cultures from eutopic or ectopic endometrium may be hindering progress in this area of research. Guidance for unbiased in vitro research methodologies in the field of reproductive science remains essential to increase confidence in the reliability of in vitro models. We present herein the protocol for a Delphi process to develop a consensus on in vitro methodologies using endometrial cells (ENDOCELL-Seud Project). A steering committee composed of leading scientists will select critical methodologies, topics and items that need to be harmonised and that will be included in a survey. An enlarged panel of experts (ENDOCELL-Seud Working Group) will be invited to participate in the survey and provide their ratings to the items to be harmonised. According to Delphi, an iterative investigation method will be adopted. Recommended measures will be finalised by the steering committee. The study received full ethical approval from the Ethical Committee of the Maastricht University (ref. FHML-REC/2021/103). The study findings will be available in both peer-reviewed articles and will also be disseminated to appropriate audiences at relevant conferences.

Lay summary

Patient-derived cells cultured in the lab are simple and cost-effective methods used to study biological and dysfunctional or disease processes. These tools are frequently used in the field of reproductive medicine. However, the lack of clear recommendations and standardised methodology to guide the laboratory work of researchers can produce results that are not always reproducible and sometimes are incorrect. To remedy this situation, we define here a method to ascertain if researchers who routinely culture cells in the lab agree or disagree on the optimal laboratory techniques. This method will be used to make recommendations for future researchers working in the field of reproductive biology to reproducibly culture endometrial cells in the laboratory.

Cabergoline Stimulates Human Endometrial Stromal Cell Decidualization and Reverses Effects of Interleukin-1β In Vitro

CONTEXT

Human embryonic implantation is regulated by neuroendocrine hormones, ovarian steroids, growth factors, and cytokines. Sympathetic innervation of the uterus also may play a role.

OBJECTIVE

We tested the hypothesis that cabergoline (Cb), an agonist of type 2 dopamine receptors (DRD2), could influence endometrial decidualization in vitro.

METHODS

Immunohistochemistry confirmed the presence of catecholaminergic neurons in human uterine tissue. DRD2 mRNA and protein expression in endometrial tissue and cells were validated by quantitative RT-PCR, cDNA microarrays, RNA sequencing, and Western blotting. Isolated human endometrial stromal cells (ESC) were subjected to dose-response and time-course experiments in the absence or presence of decidualizing hormones (10 nM estradiol, 100 nM progesterone, and 0.5 mM dibutyryl cAMP). In some cases, interleukin (IL)-1β (0.1 nM) was used as an inflammatory stimulus. Well-characterized in vitro biomarkers were quantified.

RESULTS

DRD2 were maximally expressed in vivo in the mid-secretory phase of the cycle and upregulated in ESC in response to decidualizing hormones, as were classical (eg, prolactin) and emerging (eg, VEGF and connexin 43) differentiation biomarkers. Cabergoline treatment more than doubled decidual biomarker expression, whereas risperidone, a dopamine receptor antagonist, inhibited ESC differentiation by >50%. Cabergoline induced characteristic decidual morphology changes and blocked detrimental effects of IL-1β on decidual cytology.

CONCLUSION

Our results support the hypothesis that dopaminergic neurons modulate decidualization in situ. We postulate that dopamine agonists, like Cb, could be developed as therapeutic agents to enhance implantation in couples with inflammation-associated infertility.

Human Endometrial Stromal Cell Differentiation is Stimulated by PPARβ/δ Activation: New Targets for Infertility?

CONTEXT

Implantation is a reproductive bottleneck in women, regulated by fluctuations in ovarian steroid hormone concentrations. However, other nuclear receptor ligands are modifiers of endometrial differentiation leading to successful pregnancy. In the present study we analyzed the effects of peroxisome-proliferator-activated receptor β/δ (PPARβ/δ) activation on established cellular biomarkers of human endometrial differentiation (decidualization).

OBJECTIVE

The objective of this work is to test the effects of PPARβ/δ ligation on human endometrial cell differentiation.

DESIGN

Isolated primary human endometrial stromal cells (ESCs) were treated with synthetic (GW0742) or natural (all trans-retinoic acid, RA) ligands of PPARβ/δ, and also with receptor antagonists (GSK0660, PT-S58, and ST247) in the absence or presence of decidualizing hormones (10 nM estradiol, 100 nM progesterone, and 0.5 mM dibutyryl cAMP [3',5'-cyclic adenosine 5'-monophosphate]). In some cases interleukin (IL)-1β was used as an inflammatory stimulus. Time course and dose-response relationships were evaluated to determine effects on panels of well characterized in vitro biomarkers of decidualization.

RESULTS

PPARβ/δ, along with estrogen receptor α (ERα) and PR-A and PR-B, were expressed in human endometrial tissue and isolated ESCs. GW0742 treatment enhanced hormone-mediated ESC decidualization in vitro as manifested by upregulation of prolactin, insulin-like growth factor-binding protein 1, IL-11, and vascular endothelial growth factor (VEGF) secretion and also increased expression of ERα, PR-A and PR-B, and connexin 43 (Cx43). RA treatment also increased VEGF, ERα, PR-A, and PR-B and an active, nonphosphorylated isoform of Cx43. IL-1β and PPARβ/δ antagonists inhibited biomarkers of endometrial differentiation.

CONCLUSION

Ligands that activate PPARβ/δ augment the in vitro expression of biomarkers of ESC decidualization. By contrast, PPARβ/δ antagonists impaired decidualization markers. Drugs activating these receptors may have therapeutic benefits for embryonic implantation.

Treatment of endometriosis-associated pain with linzagolix, an oral gonadotropin-releasing hormone-antagonist: a randomized clinical trial

OBJECTIVE

To study the effect of a new investigational oral gonadotropin-releasing hormone antagonist, linzagolix, on endometriosis-associated pain (EAP).

DESIGN

A multinational, parallel group, randomized, placebo-controlled, double-blind, dose-ranging trial.

SETTING

Clinical centers.

PATIENT(S)

Women aged 18-45 years with surgically confirmed endometriosis and moderate-to-severe EAP.

INTERVENTION(S)

The interventions were 50, 75, 100, or 200 mg linzagolix (or matching placebo) administered once daily for 24 weeks.

MAIN OUTCOME MEASURE(S)

The primary endpoint was the number of responders (≥30% reduction in overall pelvic pain) after 12 weeks. Other endpoints included dysmenorrhea, non-menstrual pelvic pain, serum estradiol, amenorrhea, quality of life (QoL) measures, and bone mineral density (BMD).

RESULT(S)

Compared with placebo, doses ≥ 75 mg resulted in a significantly greater proportion of responders for overall pelvic pain at 12 weeks (34.5%, 61.5%, 56.4%, and 56.3% for placebo, 75, 100, and 200 mg, respectively). A similar pattern was seen for dysmenorrhea and non-menstrual pelvic pain. The effects were maintained or increased at 24 weeks. Serum estradiol was suppressed, QoL improved, and the rate of amenorrhea increased in a dose-dependent fashion. Mean BMD loss (spine) at 24 weeks was <1% at doses of 50 and 75 mg and increased in a dose-dependent fashion up to 2.6% for 200 mg. BMD of femoral neck and total hip showed a similar pattern.

CONCLUSION(S)

Linzagolix significantly reduced EAP and improved QoL at doses of 75-200 mg and decreased BMD dose-dependently.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02778399.

Interleukin-1β inhibits estrogen receptor-α, progesterone receptors A and B and biomarkers of human endometrial stromal cell differentiation: implications for endometriosis

Human blastocyst nidation in the uterus and successful pregnancy require coordinated endometrial expression of estrogen receptor (ER)-α, progesterone receptors (PR)-A and -B and the gap junction protein, connexin (Cx)43. Our prior work established that inflammation associated with conditions of reduced fecundity, particularly endometriosis, can perturb eutopic decidual function. In the current studies, we have modeled endometrial decidualization in primary human endometrial stromal cell cultures derived from normal controls (NESC) and from the eutopic endometria of women with endometriosis (EESC) to test the hypothesis that a proinflammatory cytokine, interleukin (IL)-1β, can disrupt stromal cell differentiation. The cells were grown under a standard protocol with hormones (10 nM 17β-estradiol, 100 nM progesterone and 0.5 mM dibutyryl cAMP) for up to 7 days in the absence or presence of IL-1β. Time-course experiments showed that IL-1β compromised decidual function in both NESC and EESC, which was accompanied by rapid phosphorylation of ER-α, PR and Cx43 and their cellular depletion. Inhibition of the extracellular signal-regulated kinase (ERK)1/2 pathway by a selective pharmacological blocker (PD98059) or siRNA interference, or the addition of hormones themselves, blocked the phosphorylation of ERK mediators; increased the production of steroid receptors, Cx43, prolactin, insulin-like growth factor binding protein-1 (IGFBP)-1 and vascular endothelial growth factor (VEGF) and accelerated the differentiation. The results indicate that inhibition of IL-1β can enhance decidualization in NESC and EESC in vitro. Strategies to interfere with this pathway might be implemented as an in vivo approach to enhance fertility in women with endometriosis and, potentially, other inflammatory pathologies.

OR20-04 Modeling Uterine Disorders Utilizing Adult Uterine Stem Cells

Endometriosis and uterine fibroids (leiomyomas) are benign gynecological disorders affecting 5-15% of women of reproductive age. They cause a wide range of symptoms including mild to severe pelvic pain and infertility. Due to a paucity of proper study models, hormonal and cellular mechanisms driving the pathology of endometriosis and fibroid development and growth remain unclear. Therefore, in the current study, we established 3D spheroid/organoid cultures from human uterine epithelial and Stro-1+/CD44+ myometrial stem cells and also from cells isolated from normal proliferative phase endometrium. Uterine organoid cultures were derived from endometrial epithelial and myometrial cells isolated from women who were not receiving exogenous hormones at the time of laparoscopy or hysterectomy. They were embedded in Matrigel, and grown in culture media. To determine whether spheroids/organoids were responsive to steroid hormones, the cultures were treated in presence or absence of estradiol (E2), progesterone (P4) or the combination (E2+P4) in serum free culture media. Time-dependent spheroid/organoid-growth curves and morphological analyses were used to define growth characteristics of endometrial and myometrial organoids. Subsequently, immunohistochemical colocalization of steroid hormone receptors (estrogen receptor alpha (ER-α) and progesterone receptor (PR-A\B), alpha smooth muscle actin (α-SMA; myometrial cell marker), vimentin (stromal cell marker) and E-cadherin (endometrial epithelial cell marker) was assessed. Epithelial organoids expressed only E-cadherin in the absence of hormonal treatment. Myometrial organoids expressed α-SMA and vimentin. No expression of E-cadherin was observed in myometrial organoids. However, we observed the expression of ER-α and PR-A\B when organoids were treated with E2+P4 in a time-dependent manner. Stro-1+/CD44+ myometrial stem cells differentiated into α-SMA and fibroblast/stromal cells and response to sex hormones. These findings suggest human uterine organoid cultures retained their characteristic cellular responses to E2+P4 and could be maintained long-term in ex vivo culture. Thus, the current 3D uterine organoid systems show high expansion capacity with retention of phenotypical and functional properties, which can be used for uterine pathophysiological studies, drug discoveries and drug repositioning.

Aberrant retinoic acid production in the decidua: Implications for pre-eclampsia

Fine-tuning of the endometrium during the evanescent 'window of implantation' relies upon an array of diverse and redundant signaling molecules, particularly the ovarian steroids E2 and P4, but also growth factors, eicosanoids, and vitamins including the vitamin A compounds (retinoids). Pregnancy complications such as preeclampsia (PE) can result from aberrations in the production or function of these molecules that arise during this critical period of decidual development. Such aberrations may be reflected by incomplete decidualization, reduced spiral artery modification, and/or loss of immune tolerance to the developing fetus. Our understanding of the role of the active retinoid metabolite all-trans retinoic acid (RA) in maintaining immune balance in certain tissues, along with data describing its role in decidualization, present a compelling argument that aberrant RA signaling in the decidua can play a significant role in the etiology of PE. Recent findings that decidualization and expression of the anti-angiogenic gene product, 'soluble fms-like tyrosine kinase-1' (sFLT1) are negatively correlated and that sFLT1 expression is directly inhibited by RA, provide additional evidence of the critical role of this retinoid in regulating early vascular development in the decidua. This review provides insight into the production and function of RA in the decidua and how modifications in its metabolism and signaling might lead to certain pregnancy disorders such as PE.

Reversible EMT and MET mediate amnion remodeling during pregnancy and labor

The amnion is remodeled during pregnancy to protect the growing fetus it contains, and it is particularly dynamic just before and during labor. By combining ultrastructural, immunohistochemical, and Western blotting analyses, we found that human and mouse amnion membranes during labor were subject to epithelial-to-mesenchymal transition (EMT), mediated, in part, by the p38 mitogen-activated protein kinase (MAPK) pathway responding to oxidative stress. Primary human amnion epithelial cell cultures established from amnion membranes from nonlaboring, cesarean section deliveries exhibited EMT after exposure to oxidative stress, and the pregnancy maintenance hormone progesterone (P4) reversed this process. Oxidative stress or transforming growth factor-β (TGF-β) stimulated EMT in a manner that depended on TGF-β-activated kinase 1 binding protein 1 (TAB1) and p38 MAPK. P4 stimulated the reverse transition, MET, in primary human amnion mesenchymal cells (AMCs) through progesterone receptor membrane component 2 (PGRMC2) and c-MYC. Our results indicate that amnion membrane cells dynamically transition between epithelial and mesenchymal states to maintain amnion integrity and repair membrane damage, as well as in response to inflammation and mechanical damage to protect the fetus until parturition. An irreversible EMT and the accumulation of AMCs characterize the amnion membranes at parturition.

Adiposity and Endometriosis Severity and Typology

STUDY OBJECTIVE

Prior research has collectively shown that endometriosis is inversely related to women's adiposity. The aim of this study was to assess whether this inverse relationship holds true by disease severity and typology.

DESIGN

Cross-sectional study among women with no prior diagnosis of endometriosis.

SETTING

Fourteen clinical centers in Salt Lake City, UT, and San Francisco, CA.

PATIENTS

A total of 495 women (of which 473 were analyzed), aged 18-44 years, were enrolled in the operative cohort of the Endometriosis, Natural History, Diagnosis, and Outcomes (ENDO) Study.

INTERVENTIONS

Gynecologic laparoscopy/laparotomy regardless of clinical indication.

MEASUREMENTS AND MAIN RESULTS

Participants underwent anthropometric assessments, body composition measurements, and evaluations of body fat distribution ratios before surgery. Surgeons completed a standardized operative report immediately after surgery to capture revised American Society for Reproductive Medicine staging (I-IV) and typology of disease (superficial endometriosis [SE], ovarian endometrioma [OE], and deep infiltrating endometriosis [DIE]). Linear mixed models, taking into account within-clinical-center correlation, were used to generate least square means (95% confidence intervals) to assess differences in adiposity measures by endometriosis stage (no endometriosis, I-IV) and typology (no endometriosis, SE, DIE, OE, OE + DIE) adjusting for age, race/ethnicity, and parity. Although most confidence intervals were wide and overlapping, 3 general impressions emerged: (1) women with incident endometriosis had the lowest anthropometric/body composition indicators compared with those without incident endometriosis, (2) women with stage I or IV endometriosis had lower indicators compared with women with stage II or III, and (3) women with OE and/or DIE tended to have the lowest indicators, whereas women with SE had the highest indicators.

CONCLUSION

Our research highlights that the relationship between women's adiposity and endometriosis severity and typology may be more complicated than prior research indicates.

Insulin Signaling Via Progesterone-Regulated Insulin Receptor Substrate 2 is Critical for Human Uterine Decidualization

Decidualization, the process by which fibroblastic human endometrial stromal cells (HESC) differentiate into secretory decidual cells, is a critical event during the establishment of pregnancy. It is dependent on the steroid hormone progesterone acting through the nuclear progesterone receptor (PR). Previously, we identified insulin receptor substrate 2 (IRS2) as a factor that is directly regulated by PR during decidualization. IRS2 is an adaptor protein that functionally links receptor tyrosine kinases, such as insulin receptor (IR) and insulin-like growth factor 1 receptor (IGF1R), and their downstream effectors. IRS2 expression was induced in HESC during in vitro decidualization and siRNA-mediated downregulation of IRS2 transcripts resulted in attenuation of this process. Further use of siRNAs targeted to IR or IGF1R transcripts showed that downregulation of IR, but not IGF1R, led to impaired decidualization. Loss of IRS2 transcripts in HESC suppressed phosphorylation of both ERK1/2 and AKT, downstream effectors of insulin signaling, which mediate gene expression associated with decidualization and regulate glucose uptake. Indeed, downregulation of IRS2 resulted in reduced expression and membrane localization of the glucose transporters GLUT1 and GLUT4, resulting in lowered glucose uptake during stromal decidualization. Collectively, these data suggest that the PR-regulated expression of IRS2 is necessary for proper insulin signaling for controlling gene expression and glucose utilization, which critically support the decidualization process to facilitate pregnancy. This study provides new insight into the mechanisms by which steroid hormone signaling intersects with insulin signaling in the uterus during decidualization, which has important implications for pregnancy complications associated with insulin resistance and infertility.

Preoperative Circulating Lymphocyte and Monocyte Counts Correlate with Patient Outcomes in Type I and Type II Endometrial Cancer

Tumor-associated macrophages and tumor-infiltrating lymphocytes are associated with survival in solid malignancies. Given the physiological link to peripheral immune cell counts, we evaluated if peripheral immune cell counts were predictors of outcomes in endometrial cancer. A retrospective study was completed for endometrial cancer cases between 2000 and 2010. Kaplan-Meier, bivariate, and multivariable Cox proportion hazard analyses were performed examining the relations between survival and peripheral immune cell counts. Three hundred ten patients were identified. In bivariate analyses, high monocyte counts (> 0.7 × 10⁹ cells/L) trended with decreased progression free survival (PFS) (p = 0.10) and poorer overall survival (OS) (p = 0.16). By contrast, high lymphocyte level (> 1.5 × 10⁹ cells/L) was associated with improved PFS (p = 0.008) and OS (p = 0.006). These findings were consistent for type I and type II endometrial cancers. In a multivariable Cox model, high monocyte level was associated with a greater risk of disease recurrence (hazard ratio (HR) = 1.63, p < 0.035). Other significant predictors of recurrence were age, non-endometrioid histology, and the presence of lymph vascular space invasion (LVSI). In a multivariable Cox model, high lymphocyte count trended with a lower risk of death (HR = 0.66, p = 0.07). Age, surgical stage, non-endometrioid histology, and LVSI were also associated with death in this model. In this sample of endometrial cancer patients, we found that high preoperative lymphocyte counts were associated with improved overall improved survival. High monocyte counts were associated with poorer disease-free survival outcomes. Further studies that focused on understanding tumor-antagonizing and pro-tumoral effects of lymphocytes and monocytes, respectively, in endometrial cancer are recommended.

Retinoic Acid Is a Negative Regulator of sFLT1 Expression in Decidual Stromal Cells, and Its Levels Are Reduced in Preeclamptic Decidua

sFLT1 (soluble VEGF [vascular endothelial growth factor] receptor-1) levels are increased in preeclampsia-a pathological condition of pregnancy. The mechanism of sFLT1 overexpression by gestational tissues, particularly the decidua, remains unknown. Mass spectrometry measurement of the active retinoid metabolite, all-trans retinoic acid (RA), showed significantly lower levels of RA in preeclamptic versus normotensive decidua. In this study, we investigated the involvement of RA in regulating decidual sFLT1 expression. When decidual stromal cells (DSCs) isolated from the decidua basalis of normotensive and preeclampsia placentas were treated with BMS493-a pan-RAR (RA nuclear receptor) antagonist-upregulation of sFLT1 expression was observed. Conversely, treatment with RA resulted in downregulation of sFLT1 in normotensive DSCs and preeclampsia DSCs. Unlike treatment with cAMP, which induces decidualization while downregulating sFLT1, RA treatment did not alter DSC expression of prolactin-a marker of decidualization-or FOXO1 (forkhead box protein 01)-a transcription factor required for prolactin upregulation. TFAP2A (transcription factor AP-2-alpha [activating enhancer-binding protein 2 alpha]), a different transcription factor was upregulated in normotensive DSCs but not in preeclampsia DSCs after RA treatment. Collectively, our data show that RA suppresses sFLT1 expression in DSCs independently of cellular decidualization. These findings suggest that reduced decidual RA levels may contribute to preeclampsia pathogenesis by allowing sFLT1 accumulation at the maternal-fetal interface.

Assessing research gaps and unmet needs in endometriosis

Endometriosis, a systemic disease that is often painful and chronic, affects ∼10% of reproductive-age women. The disease can have a negative impact on a patient's physical and emotional well-being, quality of life, and productivity. Endometriosis also places significant economic and social burden on patients, their families, and society as a whole. Despite its high prevalence and cost, endometriosis remains underfunded and underresearched, greatly limiting our understanding of the disease and slowing much-needed innovation in diagnostic and treatment options. Due in part to the societal normalization of women's pain and stigma around menstrual issues, there is also a lack of disease awareness among patients, health care providers, and the public. The Society for Women's Health Research convened an interdisciplinary group of expert researchers, clinicians, and patients for a roundtable meeting to review the current state of the science on endometriosis and identify areas of need to improve a woman's diagnosis, treatment, and access to quality care. Comprehensive and interdisciplinary approaches to disease management and increased education and disease awareness for patients, health care providers, and the public are needed to remove stigma, increase timely and accurate diagnosis and treatment, and allow for new advancements.

Msx Homeobox Genes Act Downstream of BMP2 to Regulate Endometrial Decidualization in Mice and in Humans

Endometrial stromal cells differentiate to form decidual cells in a process known as decidualization, which is critical for embryo implantation and successful establishment of pregnancy. We previously reported that bone morphogenetic protein 2 (BMP2) mediates uterine stromal cell differentiation in mice and in humans. To identify the downstream target(s) of BMP2 signaling during decidualization, we performed gene-expression profiling of mouse uterine stromal cells, treated or not treated with recombinant BMP2. Our studies revealed that expression of Msx2, a member of the mammalian Msx homeobox gene family, was markedly upregulated in response to exogenous BMP2. Interestingly, conditional ablation of Msx2 in the uterus failed to prevent a decidual phenotype, presumably because of functional compensation of Msx2 by Msx1, a closely related member of the Msx family. Indeed, in Msx2-null uteri, the level of Msx1 expression in the stromal cells was markedly elevated. When conditional, tissue-specific ablation of both Msx1 and Msx2 was accomplished in the mouse uterus, a dramatically impaired decidual response was observed. In the absence of both Msx1 and Msx2, uterine stromal cells were able to proliferate, but they failed to undergo terminal differentiation. In parallel experiments, addition of BMP2 to human endometrial stromal cell cultures led to a robust enhancement of MSX1 and MSX2 expression and stimulated the differentiation process. Attenuation of MSX1 and MSX2 expression by small interfering RNAs greatly reduced human stromal differentiation in vitro, indicating a conservation of their roles as key mediators of BMP2-induced decidualization in mice and women.

New models of lipopolysaccharide-induced implantation loss reveal insights into the inflammatory response

PROBLEM

Chronic endometritis, inflammation of the uterizzvvne lining caused by common gram-negative bacterial strains or mycoplasma, has been associated with unexplained implantation failure and infertility. However, limited models of bacteria-induced implantation loss exist to study the molecular changes that occur in vivo. The goal of this study was to provide a new resource to study the process of bacteria-induced inflammation and implantation loss utilizing common experimental models: C57Bl/6 mice and primary human endometrial stromal cells.

METHOD OF STUDY

Prior to implantation, mated C57Bl/6 females were administered vehicle (saline) or gram-negative bacterial lipopolysaccharide (LPS) at a range of concentrations by intraperitoneal injection. Implantation sites were counted, and uteri were harvested to evaluate the molecular changes that accompany LPS-mediated implantation loss. Primary human endometrial stromal cells were decidualized in vitro in the presence and absence of LPS. Total RNA and conditioned media were harvested to evaluate the expression of known decidualization-associated genes and various cytokines and chemokines.

RESULTS

Lipopolysaccharide treatment resulted in fewer implantation sites in mice, decreased expression of decidualization-associated genes, and altered expression and release of cytokines and chemokines. Immunohistological analysis of the uterus from LPS-exposed mice demonstrated increased apoptosis and decreased proliferation during decidualization.

CONCLUSION

Lipopolysaccharide exposure disrupted implantation and decidualization in mice and human endometrial stromal cells. This model could be used to study the pathophysiology of implantation failure in patients with chronic endometritis or to test potential therapeutic interventions.

Endometriosis as a Comorbid Condition in Chronic Fatigue Syndrome (CFS): Secondary Analysis of Data From a CFS Case-Control Study

Background: Endometriosis (EM) is a recognized co-morbid condition in women with chronic fatigue syndrome (CFS). This analysis evaluates the impact of EM on the health of women with CFS by comparing selected health characteristics and laboratory parameters in women with CFS with and without EM (CFS+EM and CFS-only). Methods: This secondary analysis included all 36 women with CFS from a cross-sectional study of CFS in Wichita, KS, conducted between 2002 and 2003. The health characteristics and laboratory parameters of interest included functioning, fatigue, CFS-related symptoms, gynecologic history, routine laboratory parameters, inflammatory markers, cortisol levels, allostatic load, and sleep parameters (overnight polysomnography). We used parametric or non-parametric tests to compare group differences in the selected health characteristics and laboratory parameters. For examining the association between EM and variables of interest, logistic regression models were performed and odds ratios (OR) with 95% confidence intervals (CI) were reported for the magnitude of associations. Statistical significance was set at 0.05 (two-sided). Results: The mean age of this study sample was 50.9 years. Of women with CFS, 36.1% reported having EM. Age and body mass index (BMI) did not differ between CFS+EM and CFS-only groups. When examining the impact of EM, compared to women with CFS-only, women with both CFS and EM were more likely to report chronic pelvic pain [OR = 9.00 (95% CI, 1.47-55.25)] and hysterectomy [OR = 10.3 (1.82-58.39)], had more CFS symptoms (6.8 ± 0.3 vs. 5.5 ± 0.3, p = 0.02), younger mean age at menopause onset (36.4 ± 3.0 vs. 47.0 ± 2.7 years, p = 0.03), higher mean number of obstructive apnea episodes per hour (20.3 vs. 4.4, p = 0.05) and reported more negative life events (15.8 vs. 4.4, p = 0.05). Other parameters did not differ significantly between the two groups. Conclusions: We found more than a third of women with CFS reported endometriosis as a comorbid condition. The endometriosis comorbidity was associated with chronic pelvic pain, earlier menopause, hysterectomy, and more CFS-related symptoms. However, endometriosis in women with CFS did not appear to further impact functioning, fatigue, inflammatory markers, or other laboratory parameters. Further investigations including younger women are warranted.

Amnion epithelial cell-derived exosomes induce inflammatory changes in uterine cells

BACKGROUND

Fetal endocrine signals are generally considered to contribute to the timing of birth and the initiation of labor. Fetal tissues under oxidative stress release inflammatory mediators that lead to sterile inflammation within the maternal-fetal interface. Importantly, these inflammatory mediators are packaged into exosomes, bioactive cell-derived extra cellular vesicles that function as vectors and transport them from the fetal side to the uterine tissues where they deposit their cargo into target cells enhancing uterine inflammatory load. This exosome-mediated signaling is a novel mechanism for fetal-maternal communication.

OBJECTIVE

This report tested the hypothesis that oxidative stress can induce fetal amnion cells to produce exosomes, which function as a paracrine intermediary between the fetus and mother and biochemically signal readiness for parturition.

STUDY DESIGN

Primary amnion epithelial cells were grown in normal cell culture (control) or exposed to oxidative stress conditions (induced by cigarette smoke extract). Exosomes were isolated from cell supernatant by sequential ultracentrifugation. Exosomes were quantified and characterized based on size, shape, and biochemical markers. Myometrial, decidual, and placental cells (BeWo) were treated with 2 × 105, 2 × 107, and 2 × 109 control or oxidative stress-derived amnion epithelial cell exosomes for 24 hours. Entry of amnion epithelial cell exosomes into cells was confirmed by confocal microscopy of fluorescent-labeled exosomes. The effect of amnion epithelial cell exosomes on target cell inflammatory status was determined by measuring production of interleukin-6, interleukin-8, interleukin-1β, tumor necrosis factor-α, and prostaglandin E2 by enzyme-linked immunosorbent assay and inflammatory gene transcription factor (nuclear factor-κβ) activation status by immunoblotting for phosphorylated RelA/p65. Localization of NANOG in term human myometrium and decidua obtained from women before labor and during labor was performed using immunohistochemistry. Data were analyzed by Wilcoxon-Mann-Whitney test to compare effects of exosomes from control and oxidative stress-treated amnion epithelial cells on inflammatory status of target cells.

RESULTS

Amnion epithelial cells released ∼125 nm, cup-shaped exosomes with ∼899 and 1211 exosomes released per cell from control and oxidative stress-induced cells, respectively. Amnion epithelial cell exosomes were detected in each target cell type after treatment using confocal microscopy. Treatment with amnion epithelial cell exosomes increased secretion of interleukin-6, interleukin-8, and PGE2 and activation of NF-κβ (each P < .05) in myometrial and decidual cells. Exosome treatments had no effect on interleukin-6 and PGE2 production in BeWo cells. NANOG staining was higher in term labor myometrium and decidua compared to tissues not in labor.

CONCLUSION

In vitro, amnion epithelial cell exosomes lead to an increased inflammatory response in maternal uterine cells whereas placental cells showed refractoriness. Fetal cell exosomes may function to signal parturition by increasing maternal gestational cell inflammation.

Curcumin attenuates proangiogenic and proinflammatory factors in human eutopic endometrial stromal cells through the NF-κB signaling pathway

Endometriosis is a chronic gynecological inflammatory disorder in which immune system dysregulation is thought to play a role in its initiation and progression. Due to altered sex steroid receptor concentrations and other signaling defects, eutopic endometriotic tissues have an attenuated response to progesterone. This progesterone-resistance contributes to lesion survival, proliferation, pain, and infertility. The current agency-approved hormonal therapies, including synthetic progestins, GnRH agonists, and danazol are often of limited efficacy and counterproductive to fertility and cause systemic side effects due to suppression of endogenous steroid hormone levels. In the current study, we examined the effects of curcumin (CUR, diferuloylmethane), which has long been used as an anti-inflammatory folk medicine in Asian countries for this condition. The basal levels of proinflammatory and proangiogenic chemokines and cytokines expression were higher in primary cultures of stromal cells derived from eutopic endometrium of endometriosis (EESC) subjects compared with normal endometrial stromal cells (NESC). The treatment of EESC and NESC with CUR significantly and dose-dependently reduced chemokine and cytokine secretion over the time course. Notably, CUR treatment significantly decreased phosphorylation of the IKKα/β, NF-κB, STAT3, and JNK signaling pathways under these experimental conditions. Taken together, our findings suggest that CUR has therapeutic potential to abrogate aberrant activation of chemokines and cytokines, and IKKα/β, NF-κB, STAT3, and JNK signaling pathways to reduce inflammation associated with endometriosis.

Systemic Iron Deficiency in a Nonhuman Primate Model of Endometriosis

Endometriosis is characterized by endometrial tissue development outside the uterus. Anemia and iron depletion do not commonly accompany endometriosis in women, despite chronic abdominal inflammation and heavy menstrual bleeding. The objective of this study was to examine iron kinetics associated with endometriosis by using a NHP model, to better understand the underlying mechanism of abnormal hematogram values in women with endometriosis. Hematologic data from 46 macaques with endometriosis were examined for signs of iron depletion. Bone marrow, liver, and serum were used to elucidate whether iron loss or inflammation best explained the hematologic findings. Additional serum markers and intestinal biopsies from NHP with and without endometriosis were evaluated for patterns in iron kinetics across the menstrual cycle and for relative dietary iron-absorbing capacity. Almost half of the NHP with endometriosis were anemic. Overall, NHP had decreased RBC counts, increased MCV, increased percentage of reticulocytes, decreased serum hepcidin, and decreased hepatic and bone marrow iron. Intestinal expression of ferroportin 1, a mediator of iron absorption, was increased, indicating that despite high dietary iron, intestinal iron absorption did not compensate for iron losses. We concluded that use of oral iron supplementation alone does not replenish iron stores in endometriosis. Consequently, iron stores should be evaluated in women with endometriosis, even without overt clinical signs of anemia.

IL-1β Stimulates Brain-Derived Neurotrophic Factor Production in Eutopic Endometriosis Stromal Cell Cultures: A Model for Cytokine Regulation of Neuroangiogenesis

Endometriosis implants are comprised of glandular and stromal elements, macrophages, nerves, and blood vessels and are commonly accompanied by pelvic pain. We propose that activated macrophages are recruited to and infiltrate nascent lesions, where they secrete proinflammatory cytokines, promoting the production of chemokines, neurotrophins, and angiogenic growth factors that sustain an inflammatory microenvironment. Immunohistochemical evaluation of endometriosis lesions reveals in situ colocalization of concentrated macrophages, brain-derived neurotrophic factor (BDNF), and nerve fibers. These observations were coupled with biochemical analyses of primary eutopic endometriosis stromal cell (EESC) cultures, which allowed defining potential pathways leading to the neuroangiogenic phenotype of these lesions. Our findings indicate that IL-1β potently (EC₅₀ = 7 ± 2 ng/mL) stimulates production of EESC BDNF at the mRNA and protein levels in an IL-1 receptor-dependent fashion. Selective kinase inhibitors demonstrate that this IL-1β effect is mediated by c-Jun N-terminal kinase (JNK), NF-κB, and mechanistic target of rapamycin signal transduction pathways. IL-1β regulation of regulated on activation normal T cell expressed and secreted (RANTES), a prominent EESC chemokine, also relies on JNK and NF-κB. An important clinical implication of the study is that interference with BDNF and RANTES production, by selectively targeting the JNK and NF-κB cascades, may offer a tractable therapeutic strategy to mitigate the pain and inflammation associated with endometriosis.

Physiological and pathological implications of retinoid action in the endometrium

Retinol (vitamin A) and its derivatives, collectively known as retinoids, are required for maintaining vision, immunity, barrier function, reproduction, embryogenesis and cell proliferation and differentiation. Despite the fact that most events in the endometrium are predominantly regulated by steroid hormones (estrogens and progesterone), accumulating evidence shows that retinoid signaling is also involved in the development and maintenance of the endometrium, stromal decidualization and blastocyst implantation. Moreover, aberrant retinoid metabolism seems to be a critical factor in the development of endometriosis, a common gynecological disease, which affects up to 10% of reproductive age women and is characterized by the ectopic localization of endometrial-like tissue in the pelvic cavity. This review summarizes recent advances in research on the mechanisms and molecular actions of retinoids in normal endometrial development and physiological function. The potential roles of abnormal retinoid signaling in endometriosis are also discussed. The objectives are to identify limitations in current knowledge regarding the molecular actions of retinoids in endometrial biology and to stimulate new investigations toward the development potential therapeutics to ameliorate or prevent endometriosis symptoms.

Pathogenesis of endometriosis: Interaction between Endocrine and inflammatory pathways

Despite an estimated prevalence of 11% in women and plausible historical descriptions dating back to the 17th century, the etiology of endometriosis remains poorly understood. Classical theories of the histological origins of endometriosis are reviewed below. Clinical presentations are variable, and signs and symptoms do not correlate well with the extent of disease. In this summary, we have attempted to synthesize the growing evidence that hormonal and immune factors conspire to activate a local inflammatory microenvironment that encourages endometriosis to persist and elaborate mediators of its two cardinal symptoms: pain and infertility. Surprisingly, in the search for novel therapeutics for medical treatment of endometriosis, some compounds appear to have dual pharmacological functions, simultaneously modifying the endocrine and immune system facets of this complex gynecologic syndrome. We predict that these lead drugs will provide more therapeutic choices for patients in the future.

Characterization of Molecular Changes in Endometrium Associated With Chronic Use of Progesterone Receptor Modulators: Ulipristal Acetate Versus Mifepristone

Ulipristal acetate (UPA) is a selective progesterone receptor modulator (PRM), which is used as an emergency contraceptive in women. Recent studies demonstrated the efficacy of an UPA contraceptive vaginal ring (UPA-CVR) as a blocker of ovulation. However, the endometrium of women exposed to UPA over a 6-month period display glandular changes, termed PRM-associated endometrial changes (PAECs). We, therefore, investigated whether UPA-induced PAECs are associated with altered expression of the transcription factor heart- and neural crest derivatives-expressed protein 2 (HAND2) whose downregulation is observed in endometrial epithelial hyperplasia and cancer. Our results showed that while exposure to mifepristone, a well-known PRM, leads to suppression of endometrial HAND2 expression, long-term exposure to UPA-CVR did not cause downregulation of this marker. Further studies, using human primary endometrial stromal cells, confirmed that whereas mifepristone-mediated suppression of HAND2 elevated the levels of its downstream target fibroblast growth factor 18, UPA did not significantly alter the expression of this growth factor. A rationale for the differential regulation of HAND2 by these PRMs was provided by our observation that mifepristone-bound progesterone receptors turn over at a faster rate than those bound to UPA. Collectively, these results support the selective effects of different PRMs and indicate that chronic exposure to UPA does not alter the HAND2 pathway whose dysregulation is linked to complex atypical endometrial hyperplasia and cancer. The results from this study involving a limited number of clinical samples should pave the way for a larger study to determine the safety of UPA for long-term use.

IL-1β Inhibits Connexin 43 and Disrupts Decidualization of Human Endometrial Stromal Cells Through ERK1/2 and p38 MAP Kinase

Inflammation can interfere with endometrial receptivity. We examined how interleukin 1β (IL-1β) affects expression of the uterine gap junction protein connexin 43 (Cx43), which is known to be critical for embryonic implantation. We used an in vitro model of human endometrial stromal cells (ESCs), Western blotting, and a combination of validated, selective kinase inhibitors to evaluate five canonical IL-1β signaling pathways. Cx43 and two other markers of ESC differentiation (prolactin and VEGF) were inhibited predominantly via IL-1β-activated ERK1/2 and p38 MAP kinase cascades. The findings were corroborated using small interfering RNA to silence critical genes in either pathway. By contrast, upregulation of endogenous pro-IL-1α and pro-IL-1β following recombinant IL-1β treatment was mediated via the Jun N-terminal kinase pathway. The clinicopharmacological significance of our findings is that multiple signaling cascades may need to be neutralized to reverse deleterious effects of IL-1β on human endometrial function.

Pioneer Factors FOXA1 and FOXA2 Assist Selective Glucocorticoid Receptor Signaling in Human Endometrial Cells

Successful pregnancy relies on dynamic control of cell signaling to achieve uterine receptivity and the necessary biological changes required for endometrial decidualization, embryo implantation, and fetal development. Glucocorticoids are master regulators of intracellular signaling and can directly regulate embryo implantation and endometrial remodeling during murine pregnancy. In immortalized human uterine cells, we have shown that glucocorticoids and estradiol (E2) coregulate thousands of genes. Recently, glucocorticoids and E2 were shown to coregulate the expression of Left-right determination factor 1 (LEFTY1), previously implicated in the regulation of decidualization. To elucidate the molecular mechanism by which glucocorticoids and E2 regulate the expression of LEFTY1, immortalized and primary human endometrial cells were evaluated for gene expression and receptor recruitment to regulatory regions of the LEFTY1 gene. Glucocorticoid administration induced expression of LEFTY1 messenger RNA and protein and recruitment of the glucocorticoid receptor (GR) and activated polymerase 2 to the promoter of LEFTY1. Glucocorticoid-mediated recruitment of GR was dependent on pioneer factors FOXA1 and FOXA2. E2 was found to antagonize glucocorticoid-mediated induction of LEFTY1 by reducing recruitment of GR, FOXA1, FOXA2, and activated polymerase 2 to the LEFTY1 promoter. Gene expression analysis identified several genes whose glucocorticoid-dependent induction required FOXA1 and FOXA2 in endometrial cells. These results suggest a molecular mechanism by which E2 antagonizes GR-dependent induction of specific genes by preventing the recruitment of the pioneer factors FOXA1 and FOXA2 in a physiologically relevant model.

Discovery and Characterization of Human Amniochorionic Membrane Microfractures

This study obtained visual evidence of novel cellular and extracellular matrix-level structural alterations in term and preterm human fetal amniochorionic membranes. Amniochorions were collected from term cesarean (not in labor) or vaginal (labor) deliveries, preterm premature rupture of membranes, and spontaneous preterm birth. To determine the effect of oxidative stress on membranes at term or preterm labor, term not in labor samples in an organ explant culture in vitro were exposed to cigarette smoke extract. Tissues were imaged using multiphoton autofluorescence and second harmonic generation microscopy. Images were analyzed using ImageJ and IMARIS software. Three-dimensional microscopic analysis of membranes revealed microfractures that were characterized by amnion cell puckering, basement membrane degradation, and tunnels that extended into the collagen matrix with migrating cells. Numbers of microfractures were similar at term regardless of labor status; however, morphometric measures (width and depth) were higher in term labor membranes. Oxidative stress induced higher numbers of microfractures in term not in labor membranes, with morphometry resembling that seen in term labor membranes. Preterm premature rupture of the membranes had the highest number of microfractures compared to membranes from term and other preterm births. Microfractures are structural alterations indicative of areas of tissue remodeling during gestation. Their increase at preterm and in response to oxidative stress may indicate failure to reseal, predisposing membranes to rupture.

Research Priorities for Endometriosis

The 3rd International Consensus Workshop on Research Priorities in Endometriosis was held in São Paulo on May 4, 2014, following the 12th World Congress on Endometriosis. The workshop was attended by 60 participants from 19 countries and was divided into 5 main sessions covering pathogenesis/pathophysiology, symptoms, diagnosis/classification/prognosis, disease/symptom management, and research policy. This research priorities consensus statement builds on earlier efforts to develop research directions for endometriosis. Of the 56 research recommendations from the 2011 meeting in Montpellier, a total of 41 remained unchanged, 13 were updated, and 2 were deemed to be completed. Fifty-three new research recommendations were made at the 2014 meeting in Sao Paulo, which in addition to the 13 updated recommendations resulted in a total of 66 new recommendations for research. The research recommendations published herein, as well as those from the 2 previous papers from international consensus workshops, are an attempt to promote high-quality research in endometriosis by identifying and agreeing on key issues that require investigation. New areas included in the 2014 recommendations include infertility, patient stratification, and research in emerging nations, in addition to an increased focus on translational research. A revised and updated set of research priorities that builds on this document will be developed at the 13th World Congress on Endometriosis to be held on May 17-20, 2017, in Vancouver, British Columbia, Canada.

Programmed Fetal Membrane Senescence and Exosome-Mediated Signaling: A Mechanism Associated With Timing of Human Parturition

Human parturition is an inflammatory process that involves both fetal and maternal compartments. The precise immune cell interactions have not been well delineated in human uterine tissues during parturition, but insights into human labor initiation have been informed by studies in animal models. Unfortunately, the timing of parturition relative to fetal maturation varies among viviparous species-indicative of different phylogenetic clocks and alarms-but what is clear is that important common pathways must converge to control the birth process. Herein, we hypothesize a novel signaling mechanism initiated by human fetal membrane aging and senescence-associated inflammation. Programmed events of fetal membrane aging coincide with fetal growth and organ maturation. Mechanistically, senescence involves in telomere shortening and activation of p38 mitogen-activated signaling kinase resulting in aging-associated phenotypic transition. Senescent tissues release inflammatory signals that are propagated via exosomes to cause functional changes in maternal uterine tissues. In vitro, oxidative stress causes increased release of inflammatory mediators (senescence-associated secretory phenotype and damage-associated molecular pattern markers) that can be packaged inside the exosomes. These exosomes traverse through tissues layers, reach maternal tissues to increase overall inflammatory load transitioning them from a quiescent to active state. Animal model studies have shown that fetal exosomes can travel from fetal to the maternal side. Thus, aging fetal membranes and membrane-derived exosomes cargo fetal signals to the uterus and cervix and may trigger parturition. This review highlights a novel hypothesis in human parturition research based on data from ongoing research using human fetal membrane model system.

A Western Primer of Chinese Herbal Therapy in Endometriosis and Infertility

Endometriosis is a disease that affects approximately 10% of all reproductive-aged women and the prevalence rises to 20–50% in infertile women. There is growing evidence that medicinal Chinese herbs with pain-alleviating and anti-inflammatory properties may be useful in the treatment of endometriosis and infertility, but the mechanisms of action of these herbs have yet to be investigated. In addition, studies of adequate design, sample size and appropriate control are lacking. Therefore, prospective randomized, controlled studies to evaluate the efficacy, mechanism of action and toxicities of Chinese herbs in the treatment endometriosis and infertility are needed.

Relative Expression of 1,25-Dihydroxyvitamin D3 Receptor, Vitamin D 1α-Hydroxylase, Vitamin D 24-Hydroxylase, and Vitamin D 25-Hydroxylase in Endometriosis and Gynecologic Cancers

The authors demonstrate expression of the vitamin D receptor (VDR) and its hydroxylases in the endometrium and ovaries of women with and without endometriosis and endometrial or ovarian cancer. Immunohistochemistry showed strong staining of the VDR in endometriosis and endometrial cancer, with the most intense staining in epithelial cells. The VDR mRNA was significantly increased in patients with endometrial and ovarian cancer compared to the control group. There was a significantly higher 1 alpha-hydroxylase expression in the endometrium of patients with endometriosis compared to healthy controls. The observed differences in VDR and 1 alpha -hydroxylase mRNA levels were maintained at the protein level. The authors found no differences in 25-OH vitamin D levels between the serum of patients with endometriosis (25.7 +/- 2.1 ng/mL, n = 46) and healthy controls (22.6 +/- 2.0 ng/mL, n = 33, P = .31). They hypothesize that vitamin D might influence the local activity of immune cells and cytokines thought to play important pathogenic roles in the development and maintenance of endometriosis.

Effects of Phorbol Dibutyrate on Cell Proliferation, Apoptosis, and Tumor Necrosis Factor-alpha Expression in Human Endometrial Adenocarcinoma Cells

OBJECTIVES

Recent evidence suggested that protein kinase C (PKC), a major cell cycle regulator in endometrial models, mimics progesterone withdrawal by inducing downstream signals. In the current study we examined the hypothesis that the PKC activator phorbol 12,13 dibutyrate (PDB) would inhibit cell proliferation and induce apoptosis in two endometrial adenocarcinoma cell (EAC) lines, HEC-1B and Ishikawa cells. We further examined whether the induction of tumor necrosis factor-alpha (TNF-alpha) might mediate these effects.

METHODS

EAC lines were cultured under standard and serum-free conditions to study the effects of PDB on cell kinetics. Cell proliferation was determined by cell count using a hemacytometer and by incorporation of (3)H thymidine into 10% trichloracetic acid-precipitable DNA. Apoptosis was determined by measuring cytoplasmic histone-associated DNA fragments. Conditioned media concentrations of TNF-alpha were measured by a commercially available enzyme-linked immunosorbent assay (ELISA). EACs were transfected with a -125-bp TNF-alpha promoter luciferase construct and treated with PDB to evaluate transcriptional activation.

RESULTS

Activation of the PKC system with PDB (10 nM) decreased cell proliferation and mitogenesis in EACs. PDB induced apoptosis in both EAC lines. EACs exhibit basal TNF-alpha gene expression and protein secretion and these were increased potently by PDB. However, neutralization of TNF-alpha by addition of anti-TNF-alpha antibodies did not prevent the suppression of mitogenesis, induction of apoptosis, or activation of TNF-alpha gene expression by PDB.

CONCLUSION

Activation of the PKC system leads to inhibition of cell proliferation, induction of apoptosis, and TNF-alpha expression in EACs. However, apoptosis in this setting does not appear to require TNF-alpha action. EACs provide an informative model to investigate aspects of endometrial epithelial remodeling that may occur under physiologic conditions of progesterone withdrawal.

Novel concepts on pregnancy clocks and alarms: redundancy and synergy in human parturition

The signals and mechanisms that synchronize the timing of human parturition remain a mystery and a better understanding of these processes is essential to avert adverse pregnancy outcomes. Although our insights into human labor initiation have been informed by studies in animal models, the timing of parturition relative to fetal maturation varies among viviparous species, indicative of phylogenetically different clocks and alarms; but what is clear is that important common pathways must converge to control the birth process. For example, in all species, parturition involves the transition of the myometrium from a relaxed to a highly excitable state, where the muscle rhythmically and forcefully contracts, softening the cervical extracellular matrix to allow distensibility and dilatation and thus a shearing of the fetal membranes to facilitate their rupture. We review a number of theories promulgated to explain how a variety of different timing mechanisms, including fetal membrane cell senescence, circadian endocrine clocks, and inflammatory and mechanical factors, are coordinated as initiators and effectors of parturition. Many of these factors have been independently described with a focus on specific tissue compartments.In this review, we put forth the core hypothesis that fetal membrane (amnion and chorion) senescence is the initiator of a coordinated, redundant signal cascade leading to parturition. Whether modified by oxidative stress or other factors, this process constitutes a counting device, i.e. a clock, that measures maturation of the fetal organ systems and the production of hormones and other soluble mediators (including alarmins) and that promotes inflammation and orchestrates an immune cascade to propagate signals across different uterine compartments. This mechanism in turn sensitizes decidual responsiveness and eventually promotes functional progesterone withdrawal in the myometrium, leading to increased myometrial cell contraction and the triggering of parturition. Linkage of these processes allows convergence and integration of the gestational clocks and alarms, prompting a timely and safe birth. In summary, we provide a comprehensive synthesis of the mediators that contribute to the timing of human labor. Integrating these concepts will provide a better understanding of human parturition and ultimately improve pregnancy outcomes.

Endometrial Stromal Decidualization Responds Reversibly to Hormone Stimulation and Withdrawal

Human endometrial stromal decidualization is required for embryo receptivity, angiogenesis, and placentation. Previous studies from our laboratories established that connexin (Cx)-43 critically regulates endometrial stromal cell (ESC) differentiation, whereas gap junction blockade prevents it. The current study evaluated the plasticity of ESC morphology and Cx43 expression, as well as other biochemical markers of cell differentiation, in response to decidualizing hormones. Primary human ESC cultures were exposed to 10 nM estradiol, 100 nM progesterone, and 0.5 mM cAMP for up to 14 days, followed by hormone withdrawal for 14 days, mimicking a biphasic ovulatory cycle. Reversible differentiation was documented by characteristic changes in cell shape. Cx43 was reversibly up- and down-regulated after the estradiol, progesterone, and cAMP treatment and withdrawal, respectively, paralleled by fluctuations in prolactin, vascular endothelial growth factor, IL-11, and glycodelin secretion. Markers of mesenchymal-epithelial transition (MET), and its counterpart epithelial-mesenchymal transition, followed reciprocal patterns corresponding to the morphological changes. Incubation in the presence of 18α-glycyrrhetinic acid, an inhibitor of gap junctions, partially reversed the expression of decidualization and MET markers. In the absence of hormones, Cx43 overexpression promoted increases in vascular endothelial growth factor and IL-11 secretion, up-regulated MET markers, and reduced N-cadherin, an epithelial-mesenchymal transition marker. The combined results support the hypothesis that Cx43-containing gap junctions and endocrine factors cooperate to regulate selected biomarkers of stromal decidualization and MET and suggest roles for both phenomena in endometrial preparation for embryonic receptivity.

Roles of Estrogen Receptor-α and the Coactivator MED1 During Human Endometrial Decidualization

The steroid hormones 17β-estradiol and progesterone are critical regulators of endometrial stromal cell differentiation, known as decidualization, which is a prerequisite for successful establishment of pregnancy. The present study using primary human endometrial stromal cells (HESCs) addressed the role of estrogen receptor-α (ESR1) in decidualization. Knockdown of ESR1 transcripts by RNA interference led to a marked reduction in decidualization of HESCs. Gene expression profiling at an early stage of decidualization indicated that ESR1 negatively regulates several cell cycle regulatory factors, thereby suppressing the proliferation of HESCs as these cells enter the differentiation program. ESR1 also controls the expression of WNT4, FOXO1, and progesterone receptor (PGR), well-known mediators of decidualization. Whereas ESR1 knockdown strongly inhibited the expression of FOXO1 and WNT4 transcripts within 24 hours of the initiation of decidualization, PGR expression remained unaffected at this early time point. Our study also revealed a major role of cAMP signaling in influencing the function of ESR1 during decidualization. Using a proteomic approach, we discovered that the cAMP-dependent protein kinase A (PKA) phosphorylates Mediator 1 (MED1), a subunit of the mediator coactivator complex, during HESC differentiation. Using immunoprecipitation, we demonstrated that PKA-phosphorylated MED1 interacts with ESR1. The PKA-dependent phosphorylation of MED1 was also correlated with its enhanced recruitment to estrogen-responsive elements in the WNT4 gene. Knockdown of MED1 transcripts impaired the expression of ESR1-induced WNT4 and FOXO1 transcripts and blocked decidualization. Based on these findings, we conclude that modulation of ESR1-MED1 interactions by cAMP signaling plays a critical role in human decidualization.

Exosomes derived from endometriotic stromal cells have enhanced angiogenic effects in vitro

Our objective has been to establish a pro-angiogenic role for exosomes in endometriosis and to determine whether a differential expression profile of cellular and exosomal microRNAs (miRNAs) exists in endometriosis. We performed an in vitro study of human primary endometrial stromal cells (ESCs) and human umbilical vein endothelial cells (HUVECs). We isolated and characterized exosomes from ESCs from five endometriosis patients and five phase-matched controls. Exosomes were characterized by transmission electron microscopy and NanoSight technology. MiRNA was assessed by deep sequencing and reverse transcription with quantitative polymerase chain reaction. Exosome uptake studies were achieved by means of confocal microscopy. The pro-angiogenic experiments were executed by treating HUVECs with ESC-derived exosomes. We observed differential profiles of exosomal miRNA expression between exosomes derived from endometriosis lesion cells and diseased eutopic stromal cells compared with exosomes derived from control ESCs. We also demonstrated autocrine cellular uptake of exosomes and paracrine functional angiogenic effects of exosomes on HUVECs. The results of this study support the hypothesis that exosomes derived from ESCs play autocrine/paracrine roles in the development of endometriosis, potentially modulating angiogenesis. The broader clinical implications are that Sampson’s theory of retrograde menstruation possibly encompasses the finding that exosomes work as intercellular communication modulators in endometriosis.

Multiple Beneficial Roles of Repressor of Estrogen Receptor Activity (REA) in Suppressing the Progression of Endometriosis

Endometriosis is an estrogen-dependent, inflammation-driven gynecologic disorder in which endometrial tissue creates inflammatory lesions at extrauterine sites, leading to pelvic pain and impaired fertility. Although dysregulated estrogen receptor (ER) signaling has been implicated, understanding of this disease is incomplete and current therapies are of limited benefit. Using an immunocompetent syngeneic murine model, we used combinations of donor uterine tissue and/or recipient host mice with partial genetic deletion of the ER coregulator, repressor of ER activity (REA) (also known as prohibitin 2), to investigate roles of REA in the contributions of donor uterine tissue and host cell influences on endometriosis establishment and progression. Ectopic lesions derived from donor tissue with half the wild-type gene dosage of REA (REA(+/-)) grown in REA(+/-) hosts displayed enhanced proliferation, vascularization, and markedly increased neuron innervation and inflammatory responses, including elevated cytokine production, nuclear factor kappa B activation, cyclooxygenase-2 expression, and immune cell infiltration. Although lesion progression was greatest when REA was reduced in both donor tissue and host animals, other donor/host combinations indicated that distinct stimulatory inputs were derived from ectopic tissue (proliferative signals) and host cells (inflammatory signals). Importantly, depletion of REA in primary human endometriotic stromal cells led to elevated proliferation and expression of cell cycle regulators. Notably, REA was significantly lower in human endometriotic tissue versus normal human endometrium. Thus, REA modulates cross talk among multiple cell types in the uterine tissue and host background, serving as a brake on the estradiol-ER axis and restraining multiple aspects that contribute to the pathologic progression of endometriosis.