Progestin-inflammatory cytokine interactions affect matrix metalloproteinase-1 and -3 expression in term decidual cells: implications for treatment of chorioamnionitis-induced preterm delivery

Perinatal outcomes among pregnant patients with peripartum coronavirus disease 2019 infection

PURPOSE

Evaluate maternal and neonatal outcomes in peripartum coronavirus disease 2019 (COVID-19) positive women.

METHODS

A retrospective cohort study was conducted, comparing outcomes between women with and without peripartum COVID-19. All singleton deliveries from June 2020 to January 2022 were included. Univariate analysis was followed by multivariate analysis.

RESULTS

Of 26,827 singleton deliveries, 563 women had peripartum COVID-19, associated with preterm deliveries both near-term and remote from term [adjusted odds ratio (aOR) 1.6 and 2.0, respectively, p = 0.007 and 0.003]. Women with peripartum COVID-19 had a significantly higher rate of disseminated intravascular coagulation (DIC) (aOR 23.0, p < 0.001). Conversely, peripartum COVID-19 peripartum COVID-19 was negatively associated with premature rupture of membranes and prolonged maternal length of stay (aOR 0.7 and 0.5, respectively, p = 0.006 and <0.001). In cesarean delivery (CDs), patients with COVID-19 had higher rate of urgent CDs (75.5 vs. 56.1%, p < 0.001), higher rate of regional anesthesia (74.5 vs. 64.9%, p = 0.049), and longer anesthesia duration (86.1 vs. 53.4 min, p < 0.001). CD rate due to non-reassuring fetal heart rate (NRFHR) was significantly higher in women with COVID-19 (29.6 vs. 17.4%, p = 0.002). Conversely, CDs rate due to history of previous single CD was significantly higher in patients without COVID-19 diagnosis (13.6 vs. 4.1%, p = 0.006). Concerning neonatal outcomes, an association has been observed between COVID-19 and low one-minute APGAR score <5, as well as neonatal COVID-19 infection (aOR 61.8 and 1.7 respectively, p < 0.001 and p = 0.037).

CONCLUSIONS

Peripartum COVID-19 is associated with preterm deliveries, urgent CDs and DIC, potentially aligning with the infection's pathophysiology and coagulation alterations.

Clinical chorioamnionitis at term is characterized by changes in the plasma concentration of CHCHD2/MNRR1, a mitochondrial protein

OBJECTIVE

Mitochondrial dysfunction was observed in acute systemic inflammatory conditions such as sepsis and might be involved in sepsis-induced multi-organ failure. Coiled-Coil-Helix-Coiled-Coil-Helix Domain Containing 2 (CHCHD2), also known as Mitochondrial Nuclear Retrograde Regulator 1 (MNRR1), a bi-organellar protein located in the mitochondria and the nucleus, is implicated in cell respiration, survival, and response to tissue hypoxia. Recently, the reduction of the cellular CHCHD2/MNRR1 protein, as part of mitochondrial dysfunction, has been shown to play a role in the amplification of inflammatory cytokines in a murine model of lipopolysaccharide-induced systemic inflammation. The aim of this study was to determine whether the plasma concentration of CHCHD2/MNRR1 changed during human normal pregnancy, spontaneous labor at term, and clinical chorioamnionitis at term.

METHODS

We conducted a cross-sectional study that included the following groups: 1) non-pregnant women (n = 17); 2) normal pregnant women at various gestational ages from the first trimester until term (n = 110); 3) women at term with spontaneous labor (n = 50); and 4) women with clinical chorioamnionitis at term in labor (n = 25). Plasma concentrations of CHCHD2/MNRR1 were assessed by an enzyme-linked immunosorbent assay.

RESULTS

1) Pregnant women at term in labor with clinical chorioamnionitis had a significantly higher plasma CHCHD2/MNRR1 concentration than those in labor without chorioamnionitis (p = .003); 2) CHCHD2/MNRR1 is present in the plasma of healthy non-pregnant and normal pregnant women without significant differences in its plasma concentrations between the two groups; 3) there was no correlation between maternal plasma CHCHD2/MNRR1 concentration and gestational age at venipuncture; and 4) plasma CHCHD2/MNRR1 concentration was not significantly different in women at term in spontaneous labor compared to those not in labor.

CONCLUSIONS

CHCHD2/MNRR1 is physiologically present in the plasma of healthy non-pregnant and normal pregnant women, and its concentration does not change with gestational age and parturition at term. However, plasma CHCHD2/MNRR1 is elevated in women at term with clinical chorioamnionitis. CHCHD2/MNRR1, a novel bi-organellar protein located in the mitochondria and the nucleus, is released into maternal plasma during systemic inflammation.

Chorioamnionitis: An Update on Diagnostic Evaluation

Chorioamnionitis remains a major cause of preterm birth and maternal and neonatal morbidity. We reviewed the current evidence for the diagnostic tests of chorioamnionitis and how this relates to clinical practice today. A comprehensive literature search and review was conducted on chorioamnionitis and intra-uterine inflammation. Data from randomized control trials and systematic reviews were prioritized. This review highlights that sterile inflammation plays an important role in chorioamnionitis and that the current tests for chorioamnionitis including clinical criteria, maternal plasma and vaginal biomarkers lack diagnostic accuracy. Concerningly, these tests often rely on detecting an inflammatory response after damage has occurred to the fetus. Care should be taken when interpreting current investigations for the diagnosis of chorioamnionitis and how they guide obstetric/neonatal management. There is an urgent need for further validation of current diagnostic tests and the development of novel, accurate, minimally invasive tests that detect subclinical intra-uterine inflammation.

Progesterone modulates extracellular heat-shock proteins and interlukin-1β in human choriodecidual after Escherichia coli infection

INTRODUCTION

Chorioamnionitis is an adverse condition in human pregnancy caused by many bacterial pathogens including Escherichia coli (E. coli); which has been associated with higher risk of preterm birth. We recently reported that human maternal decidua (MDec) tissue responds to E. coli infection by secreting extracellular heat-shock proteins (eHsp)-60, -70 and interlukin-1β (IL-1β). Previous studies have shown that progesterone (P4) regulates the immune response, but it is unknown whether P4 inhibits the secretion of eHsp. The aim of this investigation was to determine the role of P4 on the secretion of eHsp-27, -60, -70 and IL-1β in MDec after 3, 6, and 24 h of E. coli infection.

METHODS

Nine human feto-maternal interface (HFMi) tissues were included and mounted in the Transwell culture system. Only the maternal decidua (MDec) was stimulated for 3, 6 and 24 h with E. coli alone or in combination with progesterone and RU486. After each treatment, the HFMi tissue was recovered to determine histological changes and the culture medium recovered to evaluate the levels of eHsp-27, -60, -70 and IL-1β by ELISA and mRNA expression by RT-PCR.

RESULTS

No structural changes were observed in the HFMi tissue treated with P4 and RU486. However, stimulation with E. coli produces diffuse inflammation and ischemic necrosis. E. coli induced infection decreases, in time- and dose-dependent manner, eHsp-27 and increases eHsp-60, eHsp-70 and IL-1β levels. In contrast, incubation of HFMi tissue with E. coli + P4 reversed eHsp and IL-1β secretion levels relative to E. coli stimulation group but not relative to the control group. The same profile was observed on the expression of eHsp-27 and eHsp-60.

DISCUSSION

we found that progesterone modulates the anti-inflammatory (eHsp-27) and pro-inflammatory (eHsp-60 and eHsp-70) levels of eHsp induced by E. coli infection in human choriodecidual tissue. eHsp-60 and eHsp-70 levels were not completely reversed; maintaining the secretion of IL-1β, which has been associated with adverse events during pregnancy.

Maternal Infection and Preterm Birth: From Molecular Basis to Clinical Implications

As the leading cause of neonatal morbidity and mortality, preterm birth is recognized as a major public health concern around the world. The purpose of this review is to analyze the connection between infections and premature birth. Spontaneous preterm birth is commonly associated with intrauterine infection/inflammation. The overproduction of prostaglandins caused by the inflammation associated with an infection could lead to uterine contractions, contributing to preterm delivery. Many pathogens, particularly Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Gardnerella vaginalis, Ureaplasma urealyticum, Mycoplasma hominis, Actinomyces, Candida spp., and Streptococcus spp. have been related with premature delivery, chorioamnionitis, and sepsis of the neonate. Further research regarding the prevention of preterm delivery is required in order to develop effective preventive methods with the aim of reducing neonatal morbidity.

The Pathophysiology of Labor Dystocia: Theme with Variations

Abnormally prolonged labor, or labor dystocia, is a common complication of parturition. It is the indication for about half of unplanned cesarean deliveries in low-risk nulliparous women. Reducing the rate of unplanned cesarean birth in the USA has been a public health priority over the last two decades with limited success. Labor dystocia is a complex disorder due to multiple causes with a common clinical outcome of slow cervical dilation and fetal descent. A better understanding of the pathophysiologic mechanisms of labor dystocia could lead to new clinical opportunities to increase the rate of normal vaginal delivery, reduce cesarean birth rates, and improve maternal and neonatal health. We conducted a literature review of the causes and pathophysiologic mechanisms of labor dystocia. We summarize known mechanisms supported by clinical and experimental data and newer hypotheses with less supporting evidence. We review recent data on uterine preparation for labor, uterine contractility, cervical preparation for labor, maternal obesity, cephalopelvic disproportion, fetal malposition, intrauterine infection, and maternal stress. We also describe current clinical approaches to preventing and managing labor dystocia. The variation in pathophysiologic causes of labor dystocia probably limits the utility of current general treatment options. However, treatments targeting specific underlying etiologies could be more effective. We found that the pathophysiologic basis of labor dystocia is under-researched, offering wide opportunities for translational investigation of individualized labor management, particularly regarding uterine metabolism and fetal position. More precise diagnostic tools and individualized therapies for labor dystocia might lead to better outcomes. We conclude that additional knowledge of parturition physiology coupled with rigorous clinical evaluation of novel biologically directed treatments could improve obstetric quality of care.

Matrix metalloproteinases in preterm prelabor rupture of membranes in the setting of chorioamnionitis: A scoping review

Fetal or gestational membranes extend from the placenta to enclose the fetus and amniotic fluid. While the membranes spontaneously rupture at term in normal pregnancies, they can rupture prematurely before the onset of labor, termed preterm prelabor rupture of membranes (PPROM). PPROM can be triggered by bacterial infection or sterile inflammation in the membranes, known as chorioamnionitis (CAM). The membranes derive their tensile strength from a collagen-rich extracellular matrix (ECM); as such, understanding the enzymes and processes that can degrade the membrane ECM are of paramount importance. Matrix metalloproteinases (MMPs) are a class of enzymes capable of degrading collagen and other components of the ECM, and can be induced by inflammation. We used a scoping review to address the question of how MMP activity is associated with PPROM, particularly their induction due to sterile or nonsterile CAM. We have found that the most studied MMPs in PPROM were MMPs 2, 8, and 9. Additionally, some MMPs are constitutively active, while others are induced by inflammation. Mechanistic studies of the pathways that induce MMP activation are sparse, and this area is ripe for future studies. Targeting MMP activation could be a future strategy to delay or prevent PPROM.

Evaluating the diagnosis and treatment of Chlamydia trachomatis and Neisseria gonorrhoeae in pregnant women to prevent adverse neonatal consequences in Gaborone, Botswana: protocol for the Maduo study

BACKGROUND

Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are extremely common sexually transmitted infections (STIs) that are associated with adverse birth and neonatal outcomes, and the risk of vertical transmission of CT and NG during delivery is high. The majority of CT and NG infections are asymptomatic and missed by the standard of care in most countries (treatment based on symptoms). Thus, it is likely that missed maternal CT and NG infections contribute to preventable adverse health outcomes among women and children globally. This study aims to assess the effectiveness of CT and NG testing for asymptomatic pregnant women to prevent adverse neonatal outcomes, understand the inflammatory response linking CT and NG infections to adverse neonatal outcomes, and conduct an economic analysis of the CT and NG testing intervention.

METHODS

The Maduo ("results" in Setswana) is a prospective, cluster-controlled trial in Gaborone, Botswana to compare a near point-of-care CT and NG testing and treatment intervention implemented in "study clinics" with standard antenatal care (World Health Organization-endorsed "syndromic management" strategy based on signs and symptoms without laboratory confirmation) implemented in "standard of care clinics" among asymptomatic pregnant women. The primary outcome is vertical transmission of CT/NG infection. Secondary outcomes include preterm birth (delivery < 37 completed weeks of gestation) and/or low birth weight (< 2500 g). The trial will also evaluate immunological and inflammatory markers of adverse neonatal outcomes, as well as the costs and cost-effectiveness of the intervention compared with standard care.

DISCUSSION

The Maduo study will improve our understanding of the effectiveness and cost-effectiveness of CT and NG testing among asymptomatic pregnant women. It will also increase knowledge about the CT/NG-related immune responses that might drive adverse neonatal outcomes. Further, results from this study could encourage expansion of STI testing during antenatal care in low resource settings and improve maternal and neonatal health globally.

TRIAL REGISTRATION

This trial is registered with ClinicalTrials.gov (Identifier NCT04955717, First posted: July 9, 2021)).

Actions of Bisphenol A on Different Feto-Maternal Compartments Contributing to Preterm Birth

Preterm birth remains to be one of the most prevalent obstetric complications worldwide. Since there are multiple etiological factors associated with this disease process, an integrative literature search in PubMed and Scopus databases on possible mechanism of action and effect of bisphenols on exposure on human or animal placental samples in preterm birth was conducted. From 2332 articles on initial literature search, 63 studies were included for full data extraction. Altogether, several pathways were shown to be possibly affected by bisphenols, leading to dysregulations in structural and endocrine foundation in the placenta, potential induction of senescence and failure of decidualization in the decidua, and possible propagation of inflammation in the fetal membranes. Combined, these actions may eventually counteract bisphenol-induced relaxation of the myometrium and promote contractility alongside fetal membrane weakening. In totality, these individual impairments in gestation-critical processes may lead to failure of maintenance of pregnancy, and thus effecting preterm birth.

Exposure to toxic metals and per- and polyfluoroalkyl substances and the risk of preeclampsia and preterm birth in the United States: a review

Preeclampsia and preterm birth are among the most common pregnancy complications and are the leading causes of maternal and fetal morbidity and mortality in the United States. Adverse pregnancy outcomes are multifactorial in nature and increasing evidence suggests that the pathophysiology behind preterm birth and preeclampsia may be similar-specifically, both of these disorders may involve abnormalities in placental vasculature. A growing body of literature supports that exposure to environmental contaminants in the air, water, soil, and consumer and household products serves as a key factor influencing the development of adverse pregnancy outcomes. In pregnant women, toxic metals have been detected in urine, peripheral blood, nail clippings, and amniotic fluid. The placenta serves as a "gatekeeper" between maternal and fetal exposures, because it can reduce or enhance fetal exposure to various toxicants. Proposed mechanisms underlying toxicant-mediated damage include disrupted placental vasculogenesis, an up-regulated proinflammatory state, oxidative stressors contributing to prostaglandin production and consequent cervical ripening, uterine contractions, and ruptured membranes and epigenetic changes that contribute to disrupted regulation of endocrine and immune system signaling. The objective of this review is to provide an overview of studies examining the relationships between environmental contaminants in the US setting, specifically inorganic (eg, cadmium, arsenic, lead, and mercury) and organic (eg, per- and polyfluoroalkyl substances) toxicants, and the development of preeclampsia and preterm birth among women in the United States.

Effects of histone H4 hyperacetylation on inhibiting MMP2 and MMP9 in human amniotic epithelial cells and in premature rupture of fetal membranes

Histone modification is closely associated with several diseases. The aim of the current study was to investigate the associations among histone acetylation, matrix metalloproteinases (MMPs) and premature rupture of membranes (PROM) during pregnancy. A total of 180 puerperants were divided into three groups: i) Preterm-PROM (PPROM), ii) term-PROM (TPROM) and iii) full-term labor (FTL). Enzyme-linked immunosorbent assay (ELISA) kits and western blotting were used to determine the protein concentrations of MMP2, MMP9, histone deacetylase (HDAC)1, HDAC2 and HDAC6, and the protein levels of histone H4 lysine (H4K)5 and H4K8 acetylation, respectively, in three types of fetal membranes. Additionally, human amniotic epithelial cells were used to determine the effects of the HDAC inhibitors droxinostat and chidamide on cell viability, histone acetylation and the levels of MMP2, MMP9, HDAC1, HDAC2 and HDAC6 in vitro, using the Cell Counting Kit-8 assay, western blotting and ELISA, respectively. Furthermore, the effects of droxinostat and chidamide on the invasion and migration abilities of human amniotic epithelial cells were investigated using transwell assays. In fetal membranes, the activities of MMP2 and MMP9 increased in PPROM, but decreased in TPROM. Further, the expression of HDAC1 was decreased and histone hyperacetylation was increased in both PPROM and TRPOM. In vitro experiments revealed that 5 µM droxinostat and 0.5 µM chidamide selectively decreased the level of HDAC and induced acetylation of H4K5 and H4K8. Additionally, the aforementioned HDAC inhibitors reduced human amniotic epithelial cell viability, invasion and migration, and decreased the expression levels of MMP2 and MMP9. The current study revealed a high expression level of MMP2 and MMP9 in PPROM compared with TPROM and FL tissue, which was in accordance with previously published studies. Furthermore, the in vitro tests performed in the current study revealed the effect of histone H4 hyperacetylation on inhibiting MMP2 and MMP9 levels in vitro was similar to that observed in TPROM. The results obtained in the current study may be used as a theoretical guide for clinical treatment of premature rupture of membranes.

ABCA1 plays an anti-inflammatory role by affecting TLR4 at the feto-maternal interface

AIMS

This study aimed to evaluate the function and pathway of ATP-binding cassette transporter member A1 (ABCA1)-induced anti-inflammatory response in cells at the feto-maternal interface.

MAIN METHODS

The primary amniotic mesenchymal cells (AMCs), chorion cells and decidual cells were isolated from placental membranes of women with uncomplicated pregnancies at full-term (not in labor) using enzymatic digestion. Flow cytometry was used to measure the purity of isolated cells. Immunofluorescence assay was performed to detect the location of ABCA1 and toll-like receptor 4 (TLR4). Reverse transcription PCR and western blotting analyses were used to examine ABCA1, TLR4 and inflammatory factor expression in primary cells. ELISA was used to detect cytokine secretions from the primary cells.

KEY FINDINGS

ABCA1 and TLR4 were mainly located in the cell nucleus and cytoplasm of feto-maternal interface cells. ABCA1 expression remained the highest in chorion cells, medium in decidual cells, and weakest in AMCs. Upregulated expression of ABCA1 decreased expression of TLR4 and the levels of pro-inflammatory factors, but increased cytoprotective factors in all cell types. In contrast, downregulated expression of ABCA1 increased the expression of TLR4 and pro-inflammatory factors, but decreased the levels of cytoprotective factors. Downregulated ABCA1 expression followed by decreased TLR4 expression using a small interference RNA (siRNA) induced reduction of interleukin (IL)-1β and tumor necrosis factor-α (TNF-α) in all cell types.

SIGNIFICANCE

ABCA1 at feto-maternal interface acts as an anti-inflammatory role by reducing the expression of TLR4 in uncomplicated pregnancies. ABCA1 might be a potential therapeutic target for preventing gestational diseases.

The Protective Effect of Violaxanthin from Nannochloropsis oceanica against Ultraviolet B-Induced Damage in Normal Human Dermal Fibroblasts

Skin photoaging, which is mainly induced by ultraviolet B (UVB) radiation, is prevented by the application of UV-protective agents. The microalga Nannochloropsis oceanica (N. oceanica) has been primarily reported as a potential biofuel; however, in this study, we investigated whether N. oceanica extracts exerted photoprotective effects against UVB-irradiated human dermal fibroblasts (HDFs) and which single component was responsible for the protective effect of the extracts. Two extracts-pigment and nonpigment-were prepared from N. oceanica biomass. WST-1 assay and expression analysis of interleukin genes showed that the pigment extracts were not significantly cytotoxic to HDFs. Further experiments revealed that treatment with the pigment extract upregulated the expression of collagen genes and significantly blocked UVB-induced damage such as decreased cell viability and increased ROS production. Next, to investigate the pigment composition of the extracts, HPLC analysis was conducted and violaxanthin was identified as the major pigment. The UVB photoprotective effect of the pigment extracts was confirmed in violaxanthin-treated HDFs. In addition, violaxanthin significantly attenuated UVB-induced G1 phase arrest, senescence-associated β-galactosidase activation, p16 and p21 upregulation, ERK phosphorylation and the downregulation of ECM molecules in HDFs. Therefore, we concluded that violaxanthin was a potential antiphotoaging agent.

Expression and Clinical Significance of NOD-Like Receptor Protein 3 (NLRP3) and Caspase-1 in Fetal Membrane and Placental Tissues of Patients with Premature Rupture of Membrane

Background

In this study, we aimed to investigate the expression of NOD-like receptor protein 3 (NLRP3) and caspase-1 in fetal membrane and placental tissues of patients with premature rupture of membrane (PROM), and to explore their role in PROM.

Material/Methods

Ninety women participated in this study: a control group of 30 healthy pregnant women, 30 with PPROM, and 30 with TPROM. Immunohistochemistry streptavidin-peroxidase (SP) assay was used to detect the protein expression of NLRP3 and caspase-1 in the fetal membrane and placental tissues. RT-PCR was used to detect the mRNA expression of NLRP3 and caspase-1 in fetal membrane and placental tissues.

Results

The results of SP showed that NLRP3 and caspase-1 were mainly expressed in the cytoplasm of epithelial cells, mesenchymal cells, and trophoblast cells in fetal membranes, and the cytoplasm of placental syncytiotrophoblasts and vascular endothelial cells in placental tissues. The expression of NLRP3 and caspase-1 in the TPROM group was significantly higher than that in the PPROM group and control group (p<0.05), and there was a significant difference between the PPROM group and the control group. The results of RT-PCR showed that the mRNA expression level of NLRP3 and caspase-1 in the TPROM group was significantly higher than that in the PPROM group and control group (p<0.05), and the expression of NLRP3 mRNA and caspase-1 mRNA in the PPROM group was significantly different from that in the control group (p>0.05).

Conclusions

The increased expression of NLRP3 and caspase-1 in fetal membrane and placental tissues may be associated with the development of PROM.

Progesterone suppresses the lipopolysaccharide-induced pro-inflammatory response in primary mononuclear cells isolated from human placental blood

Progesterone is an essential hormone that induces deep immune adaptations favoring pregnancy maintenance. We aimed at evaluating the effects of progesterone on the synthesis of pro- and anti-inflammatory cytokines by mononuclear cells isolated from human placental blood stimulated with lipopolysaccharide, emulating an infection-inflammation environment. Mononuclear cells isolated form human placental blood were obtained from nine women undergoing elective cesarean delivery at term (not in labor), isolated by density gradient sedimentation, cultured and co-stimulated with lipopolysaccharide (500 ng/ml) from Escherichia coli in the presence or not of progesterone (0.01, 0.1, or 1.0 µM) for 24 h. Culture supernatants were assayed for pro-inflammatory (IL-1β, TNFα, IL-6), anti-inflammatory (IL-10) cytokines, chemokines (IL-8, MIP-1α) and total MMP-9 by ELISA. In comparison with basal conditions, lipopolysaccharide treatment induced IL-1β, TNFα, IL-6, IL-8, MIP-1α, and MMP-9 synthesis. lipopolysaccharide co-treatment with progesterone significantly decreased the bacterial endotoxin-induced IL-1β, TNF-α, IL-6, IL-8, and MIP-1α secretion. In contrast, co-treatment with progesterone increased the level of IL-10 secreted to the culture medium. The present results support the concept that progesterone can modulate--partially--the inflammatory response of professional immune cells isolated from placental blood. Therefore, progesterone might be part of the natural compensatory mechanism that limits the cytotoxic effects associated with an intrauterine infection process during gestation.

Endoplasmic Reticulum Stress and Homeostasis in Reproductive Physiology and Pathology

The endoplasmic reticulum (ER), comprises 60% of the total cell membrane and interacts directly or indirectly with several cell organelles i.e., Golgi bodies, mitochondria and proteasomes. The ER is usually associated with large numbers of attached ribosomes. During evolution, ER developed as the specific cellular site of synthesis, folding, modification and trafficking of secretory and cell-surface proteins. The ER is also the major intracellular calcium storage compartment that maintains cellular calcium homeostasis. During the production of functionally effective proteins, several ER-specific molecular steps sense quantity and quality of synthesized proteins as well as proper folding into their native structures. During this process, excess accumulation of unfolded/misfolded proteins in the ER lumen results in ER stress, the homeostatic coping mechanism that activates an ER-specific adaptation program, (the unfolded protein response; UPR) to increase ER-associated degradation of structurally and/or functionally defective proteins, thus sustaining ER homeostasis. Impaired ER homeostasis results in aberrant cellular responses, contributing to the pathogenesis of various diseases. Both female and male reproductive tissues undergo highly dynamic cellular, molecular and genetic changes such as oogenesis and spermatogenesis starting in prenatal life, mainly controlled by sex-steroids but also cytokines and growth factors throughout reproductive life. These reproductive changes require ER to provide extensive protein synthesis, folding, maturation and then their trafficking to appropriate cellular location as well as destroying unfolded/misfolded proteins via activating ER-associated degradation mediated proteasomes. Many studies have now shown roles for ER stress/UPR signaling cascades in the endometrial menstrual cycle, ovarian folliculogenesis and oocyte maturation, spermatogenesis, fertilization, pre-implantation embryo development and pregnancy and parturition. Conversely, the contribution of impaired ER homeostasis by severe/prolong ER stress-mediated UPR signaling pathways to several reproductive tissue pathologies including endometriosis, cancers, recurrent pregnancy loss and pregnancy complications associated with pre-term birth have been reported. This review focuses on ER stress and UPR signaling mechanisms, and their potential roles in female and male reproductive physiopathology involving in menstrual cycle changes, gametogenesis, preimplantation embryo development, implantation and placentation, labor, endometriosis, pregnancy complications and preterm birth as well as reproductive system tumorigenesis.

Current concepts in maternal-fetal immunology: Recognition and response to microbial pathogens by decidual stromal cells

Chorioamnionitis is an acute inflammation of the gestational (extraplacental) membranes, most commonly caused by ascending microbial infection. It is associated with adverse neonatal outcomes including preterm birth, neonatal sepsis, and cerebral palsy. The decidua is the outermost layer of the gestational membranes and is likely an important initial site of contact with microbes during ascending infection. However, little is known about how decidual stromal cells (DSCs) respond to microbial threat. Defining the contributions of individual cell types to the complex medley of inflammatory signals during chorioamnionitis could lead to improved interventions aimed at halting this disease. We review available published data supporting the role for DSCs in responding to microbial infection, with a special focus on their expression of pattern recognition receptors and evidence of their responsiveness to pathogen sensing. While DSCs likely play an important role in sensing and responding to infection during the pathogenesis of chorioamnionitis, important knowledge gaps and areas for future research are highlighted.

Expression of factors involved in the regulation of angiogenesis in the full-term human placenta: Effects of in vitro fertilization

The effects of assisted reproductive technologies (ARTs) on the safety of pregnancy and the resulting offspring remain controversial. Studies of placental functions, especially vasculogenesis and angiogenesis, in pregnancies established through ART are helpful for furthering our understanding of the safety of ART. This study compares the expression profiles of angiogenic factors in human term placentas obtained from natural (NAT) pregnancies vs. placentas obtained from pregnancies that resulted from ART. Term placentas were obtained from women who underwent an ART procedure (n=4), and these were compared with term placentas that were obtained from women who had experienced a spontaneous pregnancy (controls, n=4). An array analysis was performed using the Human Angiogenesis Antibody Array to detect 43 angiogenic factors and to identify which of these factors were differentially expressed between the two groups. The expression of six of these factors was greater in the ART group than in the NAT group. The levels of four of them, including vascular endothelial growth factor receptor-3 (VEGFR3), basic fibroblast growth factor (bFGF), interferon gamma (IFNG) and matrix metalloproteinase 1 (MMP1), were quantified using western blot analysis. These factors were examined using immunohistochemistry and microscopy in vascular endothelial cells or the cytoplasm and membranes of syncytiotrophoblast cells. Our finding that selected angiogenic factors exhibit altered expression profiles in ART placentas might be significant when evaluating ART safety.

Progesterone, Inflammatory Cytokine (TNF-α), and Oxidative Stress (H2O2) Regulate Progesterone Receptor Membrane Component 1 Expression in Fetal Membrane Cells

Progesterone receptor membrane component 1 (PGRMC1) is an important novel mediator of progesterone (P4) function in fetal membrane cells. We demonstrated previously that PGRMC1 is differentially expressed in fetal membranes among pregnancy subjects and diminished in preterm premature rupture of membrane subjects. In the current study, we aim to elucidate whether PGRMC1 expression is regulated by P4, tumor necrosis factor α (TNF-α), and H2O2 in fetal membrane cells. Primary cultured membrane cells were serum starved for 24 hours followed by treatments of P4, 17 hydroxyprogesterone caproate, and medroxyprogesterone 17 acetate (MPA) at 10(-7) mol/L with ethanol as vehicle control; TNF-α at 10, 20, and 50 ng/mL with phosphate-buffered saline (PBS) as control; and H2O2 at 10 and 100 μmol/L with culture media as control for 24, 48, and 72 hours. The messenger RNA (mRNA) and protein expression of PGRMC1 was quantified using polymerase chain reaction and Western blotting, respectively. We found that PGRMC1 protein expression was regulated by MPA, TNF-α, and H2O2 in a dose-dependent manner. This regulation is also specific to the type of cell (amnion, chorion, or decidua). The upregulation of PGRMC1 by MPA might be mediated through glucocorticoid receptor (GR) demonstrated using amnion and chorion cells model with GR knockdown by specific small interfering RNA transfection. The mRNA expression of PGRMC1 was decreased by H2O2 (100 μmol/L) treatment in amnion cells, which might ultimately result in downregulation of PGRMC1 protein as our data demonstrated. None of other treatments changed PGRMC1 mRNA level in these cells. We conclude that these stimuli act as regulatory factors of PGRMC1 in a cell-specific manner.

The role of decidual cells in uterine hemostasis, menstruation, inflammation, adverse pregnancy outcomes and abnormal uterine bleeding

BACKGROUND

Human pregnancy requires robust hemostasis to prevent hemorrhage during extravillous trophoblast (EVT) invasion of the decidualized endometrium, modification of spiral arteries and post-partum processes. However, decidual hemorrhage (abruption) can occur throughout pregnancy from poorly transformed spiral arteries, causing fetal death or spontaneous preterm birth (PTB), or it can promote the aberrant placentation observed in intrauterine growth restriction (IUGR) and pre-eclampsia; all leading causes of perinatal or maternal morbidity and mortality. In non-fertile cycles, the decidua undergoes controlled menstrual bleeding. Abnormal uterine bleeding (AUB) accompanying progestin-only, long-acting, reversible contraception (pLARC) accounts for most discontinuations of these safe and highly effective agents, thereby contributing to unwanted pregnancies and abortion. The aim of this study was to investigate the role of decidual cells in uterine hemostasis, menstruation, inflammation, adverse pregnancy outcomes and abnormal uterine bleeding.

METHODS

We conducted a critical review of the literature arising from PubMed searches up to December 2015, regarding in situ and in vitro expression and regulation of several specific proteins involved in uterine hemostasis in decidua and cycling endometrium. In addition, we discussed clinical and molecular mechanisms associated with pLARC-induced AUB and pregnancy complications with abruptions, chorioamnionitis or pre-eclampsia.

RESULTS

Progestin-induced decidualization of estradiol-primed human endometrial stromal cells (HESCs) increases in vivo and in vitro expression of tissue factor (TF) and type-1 plasminogen activator inhibitor (PAI-1) while inhibiting plasminogen activators (PAs), matrix metalloproteinases (MMPs), and the vasoconstrictor, endothelin-1 (ET-1). These changes in decidual cell-derived regulators of hemostasis, fibrinolysis, extracellular matrix (ECM) turnover, and vascular tone prevent hemorrhage during EVT invasion and vascular remodeling. In non-fertile cycles, progesterone withdrawal reduces TF and PAI-1 while increasing PA, MMPs and ET-1, causing menstrual-associated bleeding, fibrinolysis, ECM degradation and ischemia. First trimester decidual hemorrhage elicits later adverse outcomes including pregnancy loss, pre-eclampsia, abruption, IUGR and PTB. Decidual hemorrhage generates excess thrombin that binds to decidual cell-expressed protease-activated receptors (PARs) to induce chemokines promoting shallow placentation; such bleeding later in pregnancy generates thrombin to down-regulate decidual cell progesterone receptors and up-regulate cytokines and MMPs linked to PTB. Endometria of pLARC users display ischemia-induced excess vasculogenesis and progestin inhibition of spiral artery vascular smooth muscle cell proliferation and migration leading to dilated fragile vessels prone to bleeding. Moreover, aberrant TF-derived thrombin signaling also contributes to the pathogenesis of endometriosis via induction of angiogenesis, inflammation and cell survival.

CONCLUSION

Perivascular decidualized HESCs promote endometrial hemostasis during placentation yet facilitate menstruation through progestational regulation of hemostatic, proteolytic, and vasoactive proteins. Pathological endometrial hemorrhage elicits excess local thrombin generation, which contributes to pLARC associated AUB, endometriosis and adverse pregnancy outcomes through several biochemical mechanisms.

Clinical chorioamnionitis at term II: the intra-amniotic inflammatory response

OBJECTIVE

Recent studies indicate that clinical chorioamnionitis is a heterogeneous condition and only approximately one-half of the patients have bacteria in the amniotic cavity, which is often associated with intra-amniotic inflammation. The objective of this study is to characterize the nature of the inflammatory response within the amniotic cavity in patients with clinical chorioamnionitis at term according to the presence or absence of 1) bacteria in the amniotic cavity and 2) intra-amniotic inflammation.

MATERIALS AND METHODS

A retrospective cross-sectional case-control study was conducted to examine cytokine and chemokine concentrations in the amniotic fluid (AF). Cases consisted of women with clinical chorioamnionitis at term (n=45). Controls were women with uncomplicated pregnancies at term who did not have intra-amniotic inflammation and were in labor (n=24). Women with clinical chorioamnionitis were classified according to the results of AF cultures, broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry, and AF concentration of interleukin-6 (IL-6) into those: 1) without intra-amniotic inflammation, 2) with microbial-associated intra-amniotic inflammation, and 3) with intra-amniotic inflammation without detectable bacteria. The AF concentrations of 29 cytokines/chemokines were determined using sensitive and specific V-PLEX immunoassays.

RESULTS

1) The AF concentrations of pro- and anti-inflammatory cytokines/chemokines such as interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin-4 (IL-4), macrophage inflammatory protein-1 beta (MIP-1β), and interleukin-8 (IL-8) (except Eotaxin-3) were significantly higher in women with clinical chorioamnionitis at term than in controls (term labor without intra-amniotic inflammation); 2) patients with microbial-associated intra-amniotic inflammation, and those with intra-amniotic inflammation without detectable bacteria, had a dramatic differential expression of cytokines and chemokines in AF compared to patients with spontaneous labor without intra-amniotic inflammation. However, no difference could be detected in the pattern of the intra-amniotic inflammatory response between patients with intra-amniotic inflammation with and without detectable bacteria; and 3) in patients with clinical chorioamnionitis at term but without intra-amniotic inflammation, the behavior of cytokines and chemokines in the AF was similar to those in spontaneous labor at term.

CONCLUSIONS

Patients with clinical chorioamnionitis who had microbial-associated intra-amniotic inflammation or intra-amniotic inflammation without detectable bacteria had a dramatic upregulation of the intra-amniotic inflammatory response assessed by amniotic fluid concentrations of cytokines. A subset of patients with term clinical chorioamnionitis does not have intra-amniotic infection/inflammation, as demonstrated by elevated AF concentrations of inflammation-related proteins, when compared to women in term labor with uncomplicated pregnancies, suggesting over-diagnosis. These observations constitute the first characterization of the cytokine/chemokine network in the amniotic cavity of patients with clinical chorioamnionitis at term.

In vitro progesterone modulation on bacterial endotoxin-induced production of IL-1β, TNFα, IL-6, IL-8, IL-10, MIP-1α, and MMP-9 in pre-labor human term placenta

BACKGROUND

During human pregnancy, infection/inflammation represents an important factor that increases the risk of developing preterm labor. The purpose of this study was to determine if pre-treatment with progesterone has an immunomodulatory effect on human placenta production of endotoxin-induced inflammation and degradation of extracellular matrix markers.

METHODS

Placentas were obtained under sterile conditions from pregnancies delivered at term before the onset of labor by cesarean section. Explants from central cotyledons of 10 human placentas were pre-treated with different concentrations of progesterone (0.01, 01, 1.0 μM) and then stimulated with 1000 ng/mL of LPS of Escherichia coli. Cytokines TNFα, IL-1β, IL-6, IL-8, MIP-1α, IL-10 concentrations in the culture medium were then measured by specific ELISA. Secretion profile of MMP-9 was evaluated by ELISA and zymogram. Statistical differences were determined by one-way ANOVA followed by the appropriate ad hoc test; P < 0.05 was considered statistically significant.

RESULTS

In comparison to the explants incubated with vehicle, the LPS treatment led to a significant increase in the level of all cytokines. In comparison to the explants treated only with LPS, pre-treatment with 0.01-1.0 μM progesterone significantly blunted (73, 56, 56, 75, 25, 48 %) the secretion of TNF-α, IL-1β, IL-6, IL-8, MIP-1α, IL-10, respectively. The MMP-9 induced by LPS treatment was inhibited only with the highest concentration of progesterone. Mifepristone (RU486) blocked the immunosuppressive effect of progesterone.

CONCLUSIONS

The present results support the concept that progesterone could be part of the compensatory mechanism that limits the inflammation-induced cytotoxic effects associated with an infection process during gestation.

Progesterone inhibits in vitro fetal membrane weakening

OBJECTIVE

Inflammation/infection and abruption are leading causes of preterm premature rupture of the membranes. Recently, we identified granulocyte-macrophage colony-stimulating factor (GM-CSF) as a critical mediator of both tumor necrosis factor-α- (TNF; modeling inflammation) and thrombin-induced (modeling abruption) weakening of the fetal membranes. We found that (1) TNF and thrombin both induced GM-CSF in the choriodecidua, (2) blockade of GM-CSF action with neutralizing antibodies inhibited both TNF- and thrombin-induced fetal membrane weakening, and (3) GM-CSF alone induced fetal membrane weakening. GM-CSF is thus part of an overlap of the inflammation and abruption-induced fetal membrane weakening pathways. The effects of progesterone analogs on the pathways by which fetal membranes are weakened have not been investigated. We examined the effects of progesterone, medroxyprogesterone acetate (MPA) and 17α-hydroxyprogesterone (HP) on TNF- and thrombin-induced fetal membrane weakening.

STUDY DESIGN

Full-thickness fetal membranes from uncomplicated term repeat cesarean deliveries were mounted in Transwell inserts in Minimum Essential Medium alpha and incubated at 37°C in 5% CO2. The choriodecidua side of the fetal membrane fragments were preincubated with progesterone, MPA, HP, or vehicle for 24 hours. Fetal membranes were then exposed to TNF, thrombin, or GM-CSF on the choriodecidua side for an additional 48 hours. The fetal membrane tissues were then strength tested, and medium from the choriodecidua and amnion compartments was assayed for GM-CSF content.

RESULTS

TNF and thrombin both weakened fetal membranes and elevated media GM-CSF levels on the choriodecidua side of the fetal membrane. Pretreatment with progesterone, MPA, or HP inhibited both TNF- and thrombin-induced fetal membrane weakening and also inhibited the induced increase in GM-CSF. GM-CSF decreased fetal membrane rupture strength by 68%, which was inhibited by progestogen pretreatment with a potency order: progesterone <MPA <HP.

CONCLUSION

Progestogen pretreatment blocks TNF- and thrombin-induced fetal membrane weakening by inhibiting both the production and action of GM-CSF. These findings are consistent with the administration of progestogens in the prevention of preterm premature rupture of the membranes.

Mechanisms of chorioamnionitis-associated preterm birth: interleukin-1β inhibits progesterone receptor expression in decidual cells

In chorioamnionitis (CAM), a major cause of preterm birth (PTB), maternal-fetal inflammation of the decidua and amniochorion cause the release of cytokines that elicit cervical ripening, fetal membrane rupture and myometrial activation. We posit that this inflammatory milieu triggers PTB by inhibiting progesterone receptor (PR) expression and increasing decidual prostaglandin (PG) production. Immunohistochemical staining of decidua detected significantly lower PR levels in decidual cells (DCs) from CAM-complicated PTB. Incubation of DCs with IL-1β decreased PR expression and significantly increased PGE2 and PGF2α production and COX-2 expression. The addition of PGF2α to DC cultures also suppressed PR expression. However, the COX inhibitor, indomethacin, did not reverse IL-1β suppression of PR expression in DC cultures. Although IL-1β treatment activated the NF-KB, ERK1/2 and p38 MAPK signalling cascades in DCs, inhibition of ERK1/2 MAPK signalling alone was sufficient to completely reverse the suppression of PR levels by IL-1β. These findings suggest that CAM-associated PTB is induced at least in part by IL-1β-mediated functional progesterone withdrawal.

Agonist-Dependent Downregulation of Progesterone Receptors in Human Cervical Stromal Fibroblasts

Progesterone (P(4)) maintains uterine quiescence during the majority of pregnancy, whereas diminished progesterone receptor (PR) expression and/or activity (ie, functional P(4) withdrawal) promotes parturition. To investigate the regulation of PR expression in cervical stroma, fibroblasts from premenopausal hysterectomy specimens were prepared. Greater than 99% of the cultures were vimentin positive (mesenchymal cell marker) with only occasional cytokeratin-8 positivity (epithelial cell marker) and no evidence of CD31-positive (endothelial cell marker) cells. Cells were immunolabeled with antibodies directed against PRs (PR-A and PR-B), estrogen receptor α (ER-α), and glucocorticoid receptor-α/β (GR-α/β). All cells were uniformly immunopositive for ER-α and GR-α/β but did not express PRs. Incubation of cells with 10(-8) mol/L 17β-estradiol induced a time-dependent increase in PR-A and PR-B messenger RNAs (mRNAs) by quantitative real-time polymerase chain reactions and proteins by immunoblotting and immunofluorescence. Incubation of cervical fibroblasts with PR ligands (medroxyprogesterone acetate or Org-2058) downregulated PR-A and PR-B levels. Coincubation of cells with PR ligands plus RU-486, a PR antagonist, partially abrogated agonist-induced receptor downregulation. Dexamethasone, a pure glucocorticoid, had no inhibitory effect on PR expression. These results indicate that progestins and estrogens regulate PR expression in cervical fibroblasts. We postulate that hormonal regulation of PR expression in the cervical stroma may contribute to functional P(4) withdrawal in preparation for parturition.

The Effect of Progestins on Tumor Necrosis Factor α-Induced Matrix Metalloproteinase-9 Activity and Gene Expression in Human Primary Amnion and Chorion Cells In Vitro

BACKGROUND

Current treatment modalities for preventing preterm premature rupture of membranes are limited, but progestins may play a role. Tumor necrosis factor α (TNFα) enhances matrix metalloproteinase-9 (MMP-9) gene expression and activity in fetal membranes, contributing to membrane weakening and rupture. We previously demonstrated that progestins attenuate TNFα-induced MMP-9 activity in a cytotrophoblast cell line. However, whether they have a similar effect in primary amnion and chorion cells of fetal membranes is unknown. In this study, we evaluated the effect of progestins on basal and TNFα-induced MMP-9 activity and gene expression in primary chorion and amnion cells harvested from the fetal membranes of term nonlaboring patients.

METHODS

Primary amnion and chorion cells were isolated from fetal membranes obtained from term uncomplicated nonlaboring patients following elective cesarean delivery (n = 11). Confluent primary amnion and chorion cell cultures were both pretreated with vehicle (control), progesterone (P4), 17α-hydroxyprogesterone caproate (17P), or medroxyprogesterone acetate (MPA) at 10 M concentration for 6 hours followed by stimulation with TNFα at 10 ng/mL for an additional 24 hours. Cell cultures pretreated with the vehicle only served as the unstimulated control and the vehicle stimulated with TNFα served as the stimulated control. Both controls were assigned a value of 100 units. Cell culture medium was harvested for MMP-9 enzymatic activity quantification using gelatin zymography. Total RNA was extracted for quantifying MMP-9 gene expression using real-time quantitative PCR. Basal MMP-9 activity and gene expression data were normalized to the unstimulated control. TNFα-stimulated MMP-9 activity and gene expression were normalized to the stimulated control. The primary outcome was the effect of progestins on TNFα-induced MMP-9 enzymatic activity in term human primary amnion and chorion cells in vitro. Secondary outcomes included the effect of progestin therapy on TNFα-induced MMP-9 gene expression and on basal MMP-9 activity and gene expression in primary amnion and chorion cells in vitro.

RESULTS

Primary cells were harvested from 11 patients. Compared with the unstimulated control, TNFα increased MMP-9 activity (P = 0.005 versus control in primary amnion cells and P < 0.001 versus control in primary chorion cells) and MMP-9 gene expression (P = 0.030 versus control in primary amnion cells, P < 0.001 versus control in primary chorion cells). Compared with the unstimulated controls, MPA, but not P4 or 17P, reduced basal MMP-9 activity [mean difference (95% CI) -49.6 (-81.9, -17.3) units, P = 0.001] and gene expression [mean difference (95% CI) -53.4 (-105.9, -0.9) units, P = 0.045] in primary amnion cells. Compared with the stimulated control, MPA also reduced TNFα-induced MMP-9 activity [mean difference (95% CI) -69.0 (-91.8, -46.3) units, P < 0.001] and gene expression [mean difference (95% CI) -86.0 (-120.7, -51.3) units, P < 0.001] in primary amnion cells. Progestin pretreatment had no significant effect on basal or TNFα-induced MMP-9 activity and gene expression in primary chorion cells.

CONCLUSIONS

The inhibitory effect of MPA on both basal and TNFα-induced MMP-9 activity and gene expression in primary amnion cells demonstrate a possible mechanism by which progestins may prevent fetal membrane weakening leading to preterm premature rupture of membranes.

WAVE3-NFκB interplay is essential for the survival and invasion of cancer cells

The WAVE3 cytoskeletal protein promotes cancer invasion and metastasis. We have shown that the WAVE3-mediated activation of cancer cell invasion is due, in part, to its regulation of expression and activity of key metalloproteinases (MMPs), including MMP9, which is centrally involved in invadopodia-mediated degradation of the extracellular matrix (ECM). MMP9 is also a major NFκB target gene, suggesting a potential linkage of WAVE3 to this pathway, which we sought to investigate. Mechanistically, we found that loss of WAVE3 in cancer cells leads to inhibition of NFκB signaling as a result of a decrease in the nuclear translocation of NFκB and therefore loss of activation of NFκB target genes. Conversely, overexpression of WAVE3 was sufficient to enhance NFκB activity. Both pharmacologic and genetic manipulations of NFκB effector molecules show that the biological consequence of loss of WAVE3 function in the NFκB pathway result the inhibition of invadopodia formation and ECM degradation by cancer cells, and these changes are a consequence of decreased MMP9 expression and activity. Loss of WAVE3 also sensitized cancer cells to apoptosis and cell death driven by TNFα, through the inhibition of the AKT pro-survival pathway. Our results identify a novel function of WAVE3 in NFκB signaling, where its activity is essential for the regulation of invadopodia and ECM degradation. Therefore, targeted therapeutic inhibition of WAVE3 will sensitize cancer cells to apoptosis and cell death, and suppress cancer invasion and metastasis.

Progesterone receptor membrane component 1 as the mediator of the inhibitory effect of progestins on cytokine-induced matrix metalloproteinase 9 activity in vitro

Progesterone (P4) and the progestin, 17α-hydroxyprogesterone caproate, are clinically used to prevent preterm births (PTBs); however, their mechanism of action remains unclear. Cytokine-induced matrix metalloproteinase 9 (MMP-9) activity plays a key role in preterm premature rupture of the membranes and PTB. We demonstrated that the primary chorion cells and the HTR8/SVneo cells (cytotrophoblast cell line) do not express the classical progesterone receptor (PGR) but instead a novel progesterone receptor, progesterone receptor membrane component 1 (PGRMC1), whose role remains unclear. Using HTR8/SVneo cells in culture, we further demonstrated that 6 hours pretreatment with medroxyprogesterone acetate (MPA) and dexamethasone (Dex) but not P4 or 17α-hydroxyprogesterone hexanoate significantly attenuated tumor necrosis factor α-induced MMP-9 activity after a 24-hour incubation period. The inhibitory effect of MPA, but not Dex, was attenuated when PGRMC1 expression was successfully reduced by PGRMC1 small interfering RNA. Our findings highlight a possible novel role of PGRMC1 in mediating the effects of MPA and in modulating cytokine-induced MMP-9 activity in cytotrophoblast cells in vitro.

PAK1 regulates breast cancer cell invasion through secretion of matrix metalloproteinases in response to prolactin and three-dimensional collagen IV

p21-Activated serine-threonine kinase (PAK1) is implicated in breast cancer. We have shown previously that PAK1 is tyrosyl phosphorylated by prolactin (PRL)-activated Janus tyrosine kinase (JAK2). Although a role for both PRL and PAK1 in breast cancer is widely acknowledged, the mechanism remains poorly understood. In the present study, PRL-activated PAK1 stimulates the invasion of TMX2-28 human breast cancer cells through Matrigel. Three-dimensional (3D) collagen IV stimulates the secretion of the matrix proteases, metalloproteinase (MMP)-1 and -3 that is further enhanced by the PRL-dependent tyrosyl phosphorylation of PAK1. 3D collagen IV also stimulates the expression and secretion of MMP-2, but in contrast to MMP-1 and -3, PRL/PAK1 signaling down-regulates MMP-2 expression and secretion. In contrast, MMP-9 expression and secretion are stimulated by 3D collagen I, not collagen IV, and are not affected by PRL but are down-regulated by PAK1. MMP-1 and -3 are required and MMP-2 contributes to PRL-dependent invasion. ERK1/2 signaling appears to be required for the enhanced expression and secretion of MMP-1 and -3 and enhanced PRL-dependent invasion. p38 MAPK and c-Jun N-terminal kinase 1/2 pathways participate in production of MMP-1 and -3 as well as in PRL/PAK1-dependent cell invasion. Together, these data illustrate the complex interaction between the substratum and PRL/PAK1 signaling in human breast cancer cells and suggest a pivotal role for PRL-dependent PAK1 tyrosyl phosphorylation in MMP secretion.

Cyclic stretch augments production of neutrophil chemokines and matrix metalloproteinases-1 (MMP-1) from human decidual cells, and the production was reduced by progesterone

PROBLEM

The purpose of this study was to evaluate the impact of mechanical stretch caused by uterine contraction and progesterone (P₄) on decidual cells (DC), neutrophil chemokines, and MMP-1 expression.

METHOD OF STUDY

DC were cultured, and cyclic stretch was applied using a computer-operated cell stretch system. Interleukin (IL)-8, growth-regulated oncogene (GRO) α, matrix metalloproteinase (MMP)-1, and mRNA and/or protein expression/activity was measured using RT-PCR and ELISA. Neutrophil chemotactic activity in conditioned media was evaluated using migration assays. The effect of P₄ was also studied.

RESULTS

Cyclic mechanical stretch increased IL-8, GROα, mRNA and protein, and MMP-1 production and activity level. Supernatant from stretched cells induced neutrophil chemotactic activity significantly. P₄ suppressed the effect of stretch.

CONCLUSION

The current study demonstrates that cyclic mechanical stretch stimulates the production of neutrophil chemokines and MMP-1 from human decidual cells, and the production was reduced by progesterone. These findings suggest that decidual cells are responding to mechanical and endocrine signals and induce biochemical factors and thereby contribute to the regulation of human labor.

Abruption-induced preterm delivery is associated with thrombin-mediated functional progesterone withdrawal in decidual cells

Plasma progesterone levels remain elevated throughout human pregnancy, suggesting that reduced reproductive-tract progesterone receptor (PR) initiates labor. Placental abruption and excess thrombin generation elicit preterm delivery (PTD). PR, glucocorticoid receptor (GR), and total and p-ERK1/2 in decidual cells (DCs) and interstitial trophoblasts (IT) were assessed via immunohistochemical staining in abruption-associated PTD versus gestational-age matched control placentas, and in cultured DCs incubated with estradiol (E2) ± medroxyprogesterone acetate (MPA) ± thrombin. Immunostaining for PR was lower in DC nuclei in abruption versus control decidua and was absent from ITs; GR was higher in IT than DCs, with no abruption-related changes in either cell type; p-ERK1/2 was higher in DCs in abruption than control decidua, with total ERK 1/2 unchanged. Immunoblotting of cultured DCs demonstrated strong E2, weak MPA, and intermediate E2+MPA mediated elevation of PR-A and PR-B levels, with constitutive GR expression. In cultured DCs, thrombin inhibited PR but not GR mRNA levels, reduced PR binding to DNA and [(3)H]progesterone binding to PR, and enhanced phosphorylated but not total ERK1/2 levels. Coincubation with a specific p-ERK1/2 inhibitor reversed thrombin-enhanced p-ERK1/2 and lowered PR levels. Thus, abruption-associated PTD is initiated by functional progesterone withdrawal, as indicated by significantly reduced DC nuclear expression of PR-A and PR-B. Functional withdrawal of progesterone results in increased p-ERK1/2, and is thus one pathway initiating abruption-associated PTD.

Innate immunity, decidual cells, and preeclampsia

Preeclampsia (PE) manifested by hypertension and proteinuria complicates 3% to 8% of pregnancies and is a leading cause of fetal-maternal morbidity and mortality worldwide. It may lead to intrauterine growth restriction, preterm delivery, and long-term sequelae in women and fetuses, and consequently cause socioeconomic burden to the affected families and society as a whole. Balanced immune responses are required for the maintenance of successful pregnancy. Although not a focus of most studies, decidual cells, the major resident cell type at the fetal-maternal interface, have been shown to modulate the local immune balance by interacting with other cell types, such as bone marrow derived-immune cells, endothelial cells, and invading extravillous trophoblasts. Accumulating evidence suggests that an imbalanced innate immunity, facilitated by decidual cells, plays an important role in the pathogenesis of PE. Thus, this review will discuss the role of innate immunity and the potential contribution of decidual cells in the pathogenesis of PE.

The clinical significance of a positive Amnisure test in women with preterm labor and intact membranes

OBJECTIVE

This study was conducted to examine the frequency and clinical significance of a positive Amnisure test in patients with preterm labor and intact membranes by sterile speculum exam.

STUDY DESIGN

A retrospective cohort study was performed including 90 patients with preterm labor and intact membranes who underwent Amnisure tests prior to amniocentesis (< 72 h); most patients (n=64) also underwent fetal fibronectin (fFN) tests. Amniotic fluid (AF) was cultured for aerobic/anaerobic bacteria and genital mycoplasmas and assayed for matrix metalloproteinase-8.

RESULTS

(1) the prevalence of a positive Amnisure test was 19% (17/90); (2) patients with a positive Amnisure test had significantly higher rates of adverse pregnancy and neonatal outcomes (e.g., impending preterm delivery, intra-amniotic infection/inflammation, and neonatal morbidity) than those with a negative Amnisure test; (3) a positive test was associated with significantly increased risk of intra-amniotic infection and/or inflammation, delivery within 7, 14, or 28 days and spontaneous preterm birth (< 35 weeks) among patients with a negative fFN test.

CONCLUSIONS

A positive Amnisure test in patients with preterm labor and intact membranes is a risk factor for adverse pregnancy outcome, particularly in patients with a negative fFN test. A positive Amnisure test in patients without symptoms or signs of ROM should not be taken as an indicator that membranes have ruptured.

Human erythema and matrix metalloproteinase-1 mRNA induction, in vivo, share an action spectrum which suggests common chromophores

Matrix metalloproteinase 1 (MMP-1) is widely regarded as a biomarker of photoageing. We tested the hypothesis that MMP-1 mRNA expression and erythema share a common action spectrum by comparing the effects of erythemally equivalent doses of UVB, UVA1 and solar simulated radiation (SSR) on acute MMP-1 mRNA expression in whole human skin in vivo. Our results show comparable MMP-1 expression with all three spectra, which supports our hypothesis. The sharing of an action spectrum implies common chromophores, one of which is likely to be DNA. We have previously shown that all spectra that we used readily induce cyclobutane thymine dimers (T<>T) in human epidermis in vivo but we lack quantitative data on damage to dermal DNA. This is important because we do not know if dermal MMP-1 induction occurs via direct damage to the dermis, or indirectly via damage to the epidermis. Our results show that UVB induces about 3 times more T<>T compared with erythemally equivalent doses of UVA1, which is similar to our published epidermal data. This supports previously published work that also implicates an unknown UVA1 chromophore for erythema and MMP-1 induction. However, the distribution of the dermal DNA damage varies considerably with spectrum. In the case of UVB it is primarily in the upper dermis, but with UVA1 it is evenly distributed. Thus, irrespective of chromophores, MMP-1 induction by direct dermal damage by both spectra is possible. The practical conclusions of our data are that the small (<5%) UVB content of solar UVR is likely to be the main cause of photoageing, at least in terms of MMP-1 expression. Furthermore, prevention of erythema by sunscreen use is likely to result in reduced MMP-1 expression.

Human decidua and invasive trophoblasts are rich sources of nearly all human matrix metalloproteinases

Trophoblast cell (CTB) invasion into the maternal endometrium plays a crucial role during human embryo implantation and placentation. As for all invasive cell types, the ability of CTB to infiltrate the uterine wall is facilitated by the activity of matrix metalloproteinases (MMPs), which is regulated by tissue inhibitors of MMPs (TIMPs). There is evidence for the expression of several MMPs and TIMPs in decidua. However, published data are limited. Therefore, to set a foundation for future research, we screened a panel of healthy human deciduas obtained during first, second and third trimester of pregnancy in addition to isolated decidual cell populations for the expression of all known human MMPs and TIMPs by RT-PCR, western blot and immunohistochemistry. In the decidual samples, we detected almost all MMPs and all four TIMPs at mRNA level. While the expression of proMMP-3 and active MMP-13 and -23 was down-regulated in the course of pregnancy, the pro forms of MMP-8, -19 and -23, active MMP-9, -10, -12, -15, -16, -26 and -28, and pro- and active MMP-14 increased towards the end of gestation. All MMPs and TIMPs were expressed in uterine natural killer cells, decidual fibroblasts and/or trophoblasts, with the exception of MMP-20 and -25. In summary, a remarkably broad spectrum of MMPs was expressed at the human feto-maternal interface, reflecting the highly invasive and remodelling effect on placenta formation. It can be speculated that expression of MMPs correlates with the invasive potential of CTBs together with a crucial role in activation of labour at term.

Interplay of cytokine polymorphisms and bacterial vaginosis in the etiology of preterm delivery

Recent findings suggest that the association between inflammation-related genes and preterm delivery may be stronger in the presence of bacterial vaginosis (BV). Tumor necrosis factor-alpha (TNFα) and interleukin 1-beta (IL-1β) are pro-inflammatory cytokines capable of inducing preterm labor in non-human primates. In this study the authors tested associations among two TNFα promoter polymorphisms (-G308A and -G238A), a single IL-1β polymorphism (+C3954T), vaginal microbial findings, and risk of preterm delivery. Data were from the Pregnancy Outcomes and Community Health (POUCH) Study (n=777 term and n=230 preterm deliveries). Vaginal smears collected at mid-pregnancy (15-27 weeks gestation) were scored according to Nugent's criteria. A Nugent score of ≥ 4 was modeled as the cut-point for intermediate and positive BV. Logistic regression was used to estimate odds ratios for associations among independent covariates (vaginal flora, genotype) and preterm delivery. Results showed that women with a Nugent score of≥ 4 and the TNFα -238 A/G or A/A were at increased risk of delivering preterm (race/ethnicity adjusted OR 2.6, 95% CI 1.2, 5.8). The p-value for the genotype and Nugent score interaction=0.02. This study points to one more example of a potential gene-environment interaction in a preterm delivery pathway. Future tests of this finding will determine the robustness of these results.

Suppression of renal fibrosis by galectin-1 in high glucose-treated renal epithelial cells

Diabetic nephropathy is the most common cause of chronic kidney disease. We investigated the ability of intracellular galectin-1 (Gal-1), a prototype of endogenous lectin, to prevent renal fibrosis by regulating cell signaling under a high glucose (HG) condition. We demonstrated that overexpression of Gal-1 reduces type I collagen (COL1) expression and transcription in human renal epithelial cells under HG conditions and transforming growth factor-β1 (TGF-β1) stimulation. Matrix metalloproteinase 1 (MMP1) is stimulated by Gal-1. HG conditions and TGF-β1 treatment augment expression and nuclear translocation of Gal-1. In contrast, targeted inhibition of Gal-1 expression reduces COL1 expression and increases MMP1 expression. The Smad3 signaling pathway is inhibited, whereas two mitogen-activated protein kinase (MAPK) pathways, p38 and extracellular signal-regulated kinase (ERK), are activated by Gal-1, indicating that Gal-1 regulates these signaling pathways in COL1 production. Using specific inhibitors of Smad3, ERK, and p38 MAPK, we showed that ERK MAPK activated by Gal-1 plays an inhibitory role in COL1 transcription and that activation of the p38 MAPK pathway by Gal-1 plays a negative role in MMP1 production. Taken together, two MAPK pathways are stimulated by increasing levels of Gal-1 in the HG condition, leading to suppression of COL1 expression and increase of MMP1 expression.

Regulation of interleukin-6 expression in human decidual cells and its potential role in chorioamnionitis

Chorioamnionitis frequently precedes both genital tract and placental inflammation and is both a primary cause of maternal morbidity and a major antecedent of preterm premature rupture of the membranes (PPROM) as well as preterm delivery (PTD). In most cases of chorioamnionitis, neutrophils dominate the decidua. In a subset of these cases, a predominance of monocytes is uniquely associated with both neonatal intraventricular hemorrhage and death. The multifunctional cytokine, interleukin-6, promotes local monocyte dominance via several mechanisms. In this study, immunostaining of placental sections revealed significantly higher interleukin-6 HSCOREs in decidual cells (DCs) but not in interstitial trophoblasts, in chorioamnionitis versus gestational age-matched control placentas (P < 0.05). In confluent leukocyte-free term DCs, secreted interleukin-6 levels in incubations with estradiol-17β were increased 2500-fold by IL-1β (P < 0.05). This up-regulation was inhibited by more than 50% in parallel incubations that included medroxyprogesterone acetate (n = 12, P < 0.05). Western blotting data confirmed these enzyme-linked immunosorbent assay results; quantitative RT-PCR findings demonstrated corresponding changes in interleukin-6 mRNA levels. Specific inhibitors of signaling for both nuclear factor-κB activation and p38-mitogen-activated protein kinase, but not for protein kinase C, significantly decreased IL-1β-enhanced interleukin-6 expression levels in cultured DCs. In conclusion, in situ and in vitro results indicate that significantly enhanced interleukin-6 expression levels in DCs during chorioamnionitis could be pivotal in skewing decidual monocyte differentiation to macrophages.

Preeclampsia-related increase of interleukin-11 expression in human decidual cells

Preeclampsia is associated with increased systemic inflammation and superficial trophoblast invasion, which leads to insufficient uteroplacental blood flow. Interleukin (IL)-11 mediates pro- and anti-inflammatory processes and facilitates decidualization. To identify IL11 expression in vivo at the maternal-placental interface in preeclampsia and control specimens and to evaluate the regulatory effects of tumor necrosis factor-α (TNF) and IL1B, cytokines elevated in preeclampsia, on IL11 levels in first trimester decidual cells in vitro, placental sections were immunostained for IL11. Leukocyte-free first trimester decidual cells were incubated with estradiol (E(2))±10(-7)  mol/l medroxyprogesterone acetate±TNF or IL1B± inhibitors of the p38 MAP kinase (p38 MAPK), nuclear factor-κ B (NFKB), or protein kinase C (PKC) signaling pathways. An ELISA assessed secreted IL11 levels, and quantitative RT-PCR measured IL11 mRNA. IL11 immunoreactivity in placental sections was significantly higher in the cytoplasm of preeclamptic decidual cells versus gestational age-matched controls. Compared to decidual cells, IL11 immunostaining in neighboring trophoblast is lower, perivascular, and not different between control and preeclamptic specimens. TNF and IL1B enhanced levels of IL11 mRNA and secreted IL11 in cultured decidual cells. Specific inhibitors of the p38 MAPK and NFKB, but not PKC signaling pathways, reduced the stimulatory effect of IL1B. Expression of decidual IL11 is increased in preeclampsia and suggests a role for IL11 in the pathogenesis of preeclampsia.

Circulating levels of matrix proteases and their inhibitors in pregnant women with and without a history of recurrent pregnancy loss

BACKGROUND

We have recently shown that serum relaxin-2 levels are attenuated in women with a history of recurrent pregnancy loss (RPL). We sought to determine whether a history of RPL is also associated with changes in serum matrix metalloproteases (MMPs) and tissue inhibitors of matrix metalloproteases (TIMP) -1 and -2.

METHODS

We obtained serum from 20 pregnant women with a history of RPL and 20 age-matched pregnant women with no history of RPL (NRPL) at 6-8, 10-12, 20, and 34 weeks gestation, and from cord blood. We quantified total serum concentrations of MMP-1, MMP-3, MMP-9 and TIMP-1 and TIMP-2 by ELISA. We determined whether these serum marker levels were associated with a history of RPL and delivery before 37 weeks gestation.

RESULTS

There was no difference in the rates of miscarriage, preterm birth or prelabour rupture of fetal membranes between RPL and NRPL. However babies born to RPL were lighter than those born to NRPL. Serum MMP-1, 9, and TIMP-1 did not differ between RPL and NRPL but MMP-3 was higher in RPL vs. NRPL at 6-8 weeks (P < 0.05). Serum TIMP-2 levels were higher in RPL women at all gestations (P < 0.01). The ratio of RLX-2 (reported previously) to TIMP-2 at 10-12 weeks gestation was more strongly associated with a history of RPL than either peptide separately - area under the ROC curves for RLX-2 0.79 (95% CI 0.57 to 0.92), TIMP-2 0.83 (95% CI 0.63 to 0.95), and for RLX-2:TIMP-2 ratio 0.92 (95% CI 0.74 to 0.99).

CONCLUSIONS

Women with a history of RPL demonstrate increased serum TIMP-2 and reduced RLX-2 during a subsequent viable pregnancy. Determination of both markers in early pregnancy enhances the discrimination of women with a history of RPL. These observations suggest roles for these two peptides in early implantation and placental development. Whether these may prove to be reliable early predictive markers for subsequent pregnancy loss in the index pregnancy is unknown and will require further studies.

Geographic ancestry and markers of preterm birth

Several biomarkers associated with spontaneous preterm birth (PTB) have been discovered over the last decade. Many of these markers, such as cytokines, are associated with infection and inflammation. As such, these biomarkers represent biologically plausible candidates for assessing those at risk of PTB. However, in the early association studies of biomarker-pregnancy outcome, the geographic ancestry of subjects was not considered. Based on more recent data, it is becoming increasingly evident that these biomarkers, and a universal approach that uses a single biomarker, fail to provide adequate assessment of risk in all subjects. Rather, recent data support the conclusion that some markers associate in subjects of African descent and another nonoverlapping set associates in subjects of European descent. These data indicate that diagnostic or predictive tests will have to use different biomarkers for different sets of subjects. If this is true, it poses severe restrictions on how to predict outcome or perform tests of association, and may make it impossible to determine risk or provide proper intervention. An alternative is presented that, although not yet proven, may make it possible to use a common set of biomarkers and their relationships to assess risk.

SAR150640, a selective beta3-adrenoceptor agonist, prevents human myometrial remodelling and activation of matrix metalloproteinase in an in vitro model of chorioamnionitis

BACKGROUND AND PURPOSE

The uterine pathophysiology underlying inflammatory conditions such as chorioamnionitis remains largely unclear. As we have shown that beta(3)-adrenoceptors act as regulators of myometrial inflammation, we wanted to investigate the potential role of beta(3)-adrenoceptors in preventing uterine remodelling induced by inflammation.

EXPERIMENTAL APPROACH

The consequences of human chorioamnionitis on myometrial remodelling were characterized by Sirius Red staining and metalloproteinase (MMP) expression, and compared with the effects of incubating human myometrial samples with Escherichia coli lipopolysaccharide (LPS) in vitro. We also assessed the effect of SAR150640, a selective beta(3)-adrenoceptor agonist, on the production and activity of MMPs.

KEY RESULTS

Chorioamnionitis was associated with a 46% decrease in total collagen, as well as over-expression of MMP2 (+61%) and MMP9 (+84%); both effects were reproduced by incubation with LPS (10 microg x mL(-1), 48 h). LPS-induced over-expression of MMP2 and MMP9 in normal human myometrium was paralleled by an overactivity of the proteins. Both over-expression and overactivity were prevented by the beta(3)-adrenoceptor agonist SAR150640 in a concentration-dependent manner. SAR150640, by itself, did not exhibit any effect on MMP production in control tissues.

CONCLUSIONS AND IMPLICATIONS

This study shows that inflammation was associated with an intense remodelling of human myometrium, a process likely to be explained by MMP activation. Our study emphasizes the potential therapeutic relevance of beta(3)-adrenoceptor agonists to the treatment of preterm labour and other uterine inflammatory conditions.

Progestin and thrombin regulate tissue factor expression in human term decidual cells

CONTEXT

Perivascular cell membrane-bound tissue factor (TF) initiates hemostasis via thrombin generation. The identity and potential regulation of TF-expressing cells at the human maternal-fetal interface that confers hemostatic protection during normal and preterm delivery is unclear.

OBJECTIVES

The objective of the study were to identify TF-expressing cells at the maternal-fetal interface in term and preterm decidual sections by immunohistochemistry and evaluate progestin, thrombin, TNF-alpha, and IL-1beta effects on TF expression by cultured human term decidual cells (DCs).

INTERVENTIONS AND MAIN OUTCOME MEASURES

Serial placental sections were immunostained for TF. Leukocyte-free term DC monolayers were incubated with 10(-8) M estradiol (E2) or E2 plus 10(-7) M medroxyprogestrone acetate (MPA) +/- thrombin or TNF-alpha or IL-1beta. ELISA and Western blotting assessed TF in cell lysates. Quantitative real-time RT-PCR measured TF mRNA levels.

RESULTS

Immunolocalized TF in DC membranes in preterm and term placental sections displayed higher Histologic Scores than villous mesenchymal cells (P < 0.05). TF was undetected in interstitial or extravillous trophoblasts. Compared with DCs incubated with E2, MPA and 2.5 U/ml thrombin each doubled TF levels (P < 0.05) and E2 + MPA + thrombin further doubled TF levels (P < 0.05), whereas TNF-alpha and IL-1beta were ineffective. Western blotting confirmed the ELISA results. Quantitative RT-PCR revealed corresponding changes in TF mRNA levels.

CONCLUSIONS

In human term placental sections, DC-expressed TF exceeds that of other cell types at the maternal-fetal interface and is localized at the cell membranes in which it can bind to factor VII and meet the hemostatic demands of labor and delivery via thrombin formation. Unlike the general concept that TF is constitutive in cells that highly express it, MPA and thrombin significantly enhanced TF expression in term DC monolayers.

Inflammation and pregnancy

Inflammation is a process by which tissues respond to various insults. It is characterized by upregulation of chemokines, cytokines, and pattern recognition receptors that sense microbes and tissue breakdown products. During pregnancy, the balance of Th1 (cell-mediated immunity) and Th2 (humoral immunity) cytokines is characterized by an initial prevalence of Th2 cytokines, followed by a progressive shift toward Th1 predominance late in gestation, that when is abnormal, may initiate and intensify the cascade of inflammatory cytokine production involved in adverse pregnancy outcomes. Maternal and placental hormones may affect the inflammatory pathway. Hypoxia and the innate immune response are 2 adaptive mechanisms by which organisms respond to perturbation in organ function, playing a major role in spontaneous abortion, intrauterine growth restriction, preeclampsia, and preterm delivery. The interaction between tissue remodeling factors, like matrix metalloproteinases, and vasoactive/hemostatic factors, like prostaglandin and coagulation factors, mediates this adaptive response.

Different secretion patterns of matrix metalloproteinases and IL-8 and effect of corticotropin-releasing hormone in preterm and term cervical fibroblasts

The aims of the present study were to compare the levels of mRNA and protein expression of matrix metalloproteinase (MMP)-1, -3, -8 and -9 in human cervical tissue in preterm and term labor as well as not in labor and to determine if corticotropin-releasing hormone (CRH) has an effect on MMP-1, -3 and interleukin (IL)-8 secretion in both preterm and term cervical fibroblasts. Cervical biopsies were taken from 60 women: 18 at preterm labor, 7 at preterm not in labor, 18 at term labor and 17 at term not in labor. ELISA and Immulite were used for protein and real-time RT–PCR for mRNA analysis. Cervical fibroblast cultures were incubated for 18 h with different CRH concentrations (10⁻¹³–10⁻⁶ M). The mRNA expression of MMP-1, -3 and -9 was higher in laboring groups compared with term not in labor. Protein levels of MMP-8 and -9 were higher in term in labor group compared with non-laboring groups. There were no significant differences in mRNA and protein expression between the preterm and respective term control groups. CRH significantly increased secretion of IL-8 in preterm and term cervical fibroblasts compared with controls. The secretion of IL-8 and MMP-1 was significantly higher and MMP-3 secretion lower in preterm cervical fibroblasts. In conclusion, cervical ripening at preterm seems to be a similar inflammatory process as at term with CRH involved. However, preterm and term cervical fibroblasts might have different phenotypes based on different secretion patterns of IL-8, MMP-1 and MMP-3.