TREM-1 expression is increased in human placentas from severe early-onset preeclamptic pregnancies where it may be involved in syncytialization

Different Lengths of Gestational Exposure to Secondhand Smoke or e-Cigarette Vapor Induce the Development of Placental Disease Symptoms

Exposure to cigarette smoke is known to induce disease during pregnancy. Recent evidence showed that exposure to secondhand smoke (SHS) negatively impacts fetal and placental weights, leading to the development of intrauterine growth restriction (IUGR). Electronic cigarettes (eCigs) represent a phenomenon that has recently emerged, and their use is also steadily rising. Even so, the effects of SHS or eCigs during gestation remain limited. In the present study, we wanted to characterize the effects of SHS or eCig exposure at two different important gestational points during mouse pregnancy. C57/Bl6 mice were exposed to SHS or eCigs via a nose-only delivery system for 4 days (from 14.5 to 17.5 gestational days (dGA) or for 6 days (from 12.5 dGA to 17.5 dGA)). At the time of necropsy (18.5 dGA), placental and fetal weights were recorded, maternal blood pressure was determined, and a dipstick test to measure proteinuria was performed. Placental tissues were collected, and inflammatory molecules in the placenta were identified. Treatment with SHS showed the following: (1) a significant decrease in placental and fetal weights following four days of exposure, (2) higher systolic and diastolic blood pressure following six days of exposure, and (3) increased proteinuria after six days of exposure. Treatment with eCigs showed the following: (1) a significant decrease in placental weight and fetal weight following four or six days of exposure, (2) higher systolic and diastolic blood pressure following six days of exposure, and (3) increased proteinuria after six days of exposure. We also observed different inflammatory markers associated with the development of IUGR or PE. We conclude that the detrimental effects of SHS or eCig treatment coincide with the length of maternal exposure. These results could be beneficial in understanding the long-term effects of SHS or eCig exposure in the development of placental diseases.

Establishment and comparison of human term placenta-derived trophoblast cells†

Research on the biology of fetal-maternal barriers has been limited by access to physiologically relevant cells, including trophoblast cells. In this study, we describe the development of a human term placenta-derived cytotrophoblast immortalized cell line (hPTCCTB) derived from the basal plate. Human-term placenta-derived cytotrophoblast immortalized cell line cells are comparable to their primary cells of origin in terms of morphology, marker expression, and functional responses. We demonstrate that these can transform into syncytiotrophoblast and extravillous trophoblasts. We also compared the hPTCCTB cells to immortalized chorionic trophoblasts (hFM-CTC), trophoblasts of the chorionic plate, and BeWo cells, choriocarcinoma cell lines of conventional use. Human-term placenta-derived cytotrophoblast immortalized cell line and hFM-CTCs displayed more similarity to each other than to BeWos, but these differ in syncytialization ability. Overall, this study (1) demonstrates that the immortalized hPTCCTB generated are cells of higher physiological relevance and (2) provides a look into the distinction between the spatially distinct placental and fetal barrier trophoblasts cells, hPTCCTB and hFM-CTC, respectively.

Biomarker screening in preeclampsia: an RNA-sequencing approach based on data from multiple studies

OBJECTIVE

Biomarkers have become important in the prognosis and diagnosis of various diseases. High-throughput methods, such as RNA sequencing facilitate the detection of differentially expressed genes (DEGs), hence potential biomarker candidates. Individual studies suggest long lists of DEGs, hampering the identification of clinically relevant ones. Concerning preeclampsia - a major obstetric burden with high risk for adverse maternal and/or neonatal outcomes - limitations in diagnosis and prediction are still important issues. We, therefore, developed a workflow to facilitate the screening for biomarkers.

METHODS

On the basis of the tool DESeq2, a comprehensive workflow for identifying DEGs was established, analyzing data from several publicly available RNA-sequencing studies. We applied it to four RNA-sequencing datasets (one blood, three placenta) analyzing patients with preeclampsia and normotensive controls. We compared our results with other published approaches and evaluated their performance.

RESULTS

We identified 110 genes that are dysregulated in preeclampsia, observed in at least three of the studies analyzed, six even in all four studies. These included FLT-1, TREM-1, and FN1, which either represent established biomarkers at protein level, or promising candidates based on recent studies. For comparison, using a published meta-analysis approach, 5240 DEGs were obtained.

CONCLUSION

This study presents a data analysis workflow for preeclampsia biomarker screening, capable of identifying promising biomarker candidates, while drastically reducing the numbers of candidates. Moreover, we were also able to confirm its performance for heart failure. This approach can be applied to additional diseases for biomarker identification, and the set of DEGs identified in preeclampsia represents a resource for further studies.

TREM-1 amplifies trophoblastic inflammation via activating NF-κB pathway during preeclampsia

INTRODUCTION

Excessive activation of maternal systemic inflammation is one of the underlying causes of pathology during the disease course of preeclampsia (PE). The triggering receptor expressed on myeloid cells-1 (TREM-1) participates in the development and persistence of inflammation. We hypothesized that dysregulated TREM-1 may be involved in the pathogenesis of PE by promoting the secretion of trophoblastic pro-inflammatory cytokines that augment inflammation.

METHODS

The localization of TREM-1 in placenta and the extravillous trophoblast cell line (TEV-1) was determined by immunohistochemical staining. The expression level of TREM-1 and pro-inflammatory cytokines in placentas were compared between normal pregnancies and PE. We used lipopolysaccharide (LPS) to simulate trophoblastic inflammation. TEV-1 cells were transfected with TREM-1 plasmid and si-TREM-1 respectively, and then were incubated with LPS. The expression levels of pro-inflammatory cytokines and key molecules featured in nuclear transcription factor-kappaB (NF-κB) pathway were detected. Transwell assays were used to detect the effects of TREM-1 on cell migration and invasion.

RESULTS

TREM-1 was localized on both villous trophoblasts (VTs) and extravillous trophoblasts (EVTs). TREM-1 and pro-inflammatory cytokines were up-regulated in preeclamptic placenta. Overexpression of TREM-1 promoted the activation of NF-κB pathway and the release of pro-inflammatory factors induced by LPS, and enhanced migration and invasion of TEV-1 cells. Inhibition of TREM-1 significantly attenuated LPS-induced effects and suppressed migration and invasion.

DISCUSSION

This study suggested that TREM-1 was up-regulated in PE, and may promote the production of downstream inflammatory factors by activating NF-κB pathway in trophoblastic cells, thus exerting pro-inflammatory effects in the pathogenesis of PE.

Long intergenic ncRNA 00473 improves the invasion of trophoblastic cells via miR-16-5p

Preeclampsia (PE) is a common disease among pregnant women and is characterized by high blood pressure, edemas, proteinuria, etc. However, the underlying mechanism of PE is still not clear. Our results may provide a new understanding of the pathogenesis of PE and a therapeutical target for the treatment of the disease. Levels of long intergenic ncRNA 00473 (LINC00473), miR-16-5p, MMP2, MMP9, Bcl-2, Bax, and C caspase-3 in placental tissues or human trophoblastic cells were assessed. HTR8/SVneo and JEG-3 cells were transfected with LINC00473, miR-16-5p mimic, LINC00473 siRNA, or miR-16-5p inhibitor alone, or co-transfected with LINC00473 and miR-16-5p mimic or LINC00473 siRNA and miR-16-5p inhibitor. Viability, apoptosis, migration and invasion of cells were assessed by Cell Counting Kit-8, flow cytometry, wound healing assay and Transwell assay, respectively. The target gene of LINC00473 was analyzed using Starbase and dual-luciferase reporter assay. LINC00473 level was down-regulated in placental tissues of PE patients. LINC00473 overexpression increased cell viability, migration, invasion, and MMP2, MMP9 and Bcl-2 levels, yet decreased the apoptosis rates and Bax and C caspase-3 levels in cells; however, LINC00473 silencing had the opposite effect. LINC00473 targeted miR-16-5p and miR-16-5p level was negatively related to LINC00473 level. MiR-16-5p mimic reversed the promoting effect of LINC00473 overexpression on the invasion of HTR8/SVneo and JEG-3 cells, while miR-16-5p inhibitor reversed the inhibitory effect of LINC00473 silencing on the invasion of these cells. In conclusion, LINC00473 improved the invasion of human trophoblastic cells via miR-16-5p.

Predictive Performance of Serum β-hCG MoM Levels for Preeclampsia Screening: A Meta-Analysis

OBJECTIVE

The aim of the present study was to investigate the predictive value of using the multiple of the median (MoM) of β-human chorionic gonadotropin (β-hCG) levels in patients with preeclampsia (PE) and healthy pregnant women.

METHODS

Electronic databases including PubMed, EBSCO, Ovid, Web of Science, China National Knowledge Infrastructure (CNKI), SinoMed, Wangfang and the Weipu Journal were searched up to May 31, 2020. Two reviewers independently selected the articles and extracted data on study characteristics, quality and results. A random-effects model was employed, and standardized mean difference and 95% confidence intervals were calculated. Twenty-one case-control studies were analyzed in the present meta-analysis, including a total of 2,266 cases and 25,872 healthy controls.

RESULTS

Women who were diagnosed with PE were found to have higher early second-trimester levels of serum β-hCG MoM compared with healthy controls, although the levels in the first trimester were not significantly different. Ethnicity subgroup analysis demonstrated that the MoM of β-hCG serum levels was significantly higher in PE patients in both Asian and Caucasian populations during the early second trimester.

CONCLUSION

The MoM of β-hCG serum levels was found to be a valuable clinical indicator for predicting PE in the early second trimester, but had little predictive value in the first trimester. However, further assessment of the predictive capacity of β-hCG within larger, diverse populations is required.

A promising novel biomarker for early-onset preeclampsia: soluble trigger receptor expressed on myeloid cells-1 (sTREM-1)

BACKGROUND

We aimed to explore TREM-1 activation in pregnant women who has preeclampsia through the measurement of its soluble form sTREM.

METHODS

A prospective cohort study was conducted. Participants were recruited from antenatal clinic between 1 May 2019 and 31 August 2019, and they all provided written informed consent for participation. Women between 18 and 42 years of age who were diagnosed with early or late-onset preeclampsia (LOP) were offered participation if they did not have any known systemic disease (chronic hypertension, diabetes, hypothyroidism, chronic renal-liver diseases, etc.); autoimmune disorders; multiple pregnancies; presence of fetal structural and chromosomal anomalies; placenta previa; cholestasis of pregnancy; preterm delivery; evidence of chronic and active infection. The primary outcome of the study was to assess any difference between groups in terms of the diagnostic value of sTREM level.

RESULTS

A total of 80 patients were enrolled; proven early-onset preeclampsia (EOP) (n = 20), LOP (n = 30), and control (n = 30) groups. There was no significant difference among the groups in terms of age and BMI. Mean gestational age at diagnosis of EOP; 30 ± 1.9 and LOP; 34.7 ± 1.9 weeks gestation. The mean sTREM level was 160.130 ± 1.65 pg/ml in the EOP group, 119.337 ± 2.04 pg/ml in LOP group, and 87.764 ± 1.69 pg/ml in the control group. According to subgroup analysis, sTREM levels were significantly higher in EOP group than control group.

CONCLUSIONS

sTREM might be a promising biomarker for early detection of EOP. However, future studies are necessary to confirm this hypothesis.

GIT2 deficiency attenuates inflammation-induced expression of pro-labor mediators in human amnion and myometrial cells†

Untimely activation of the inflammatory response by sterile or infective insults in uterine tissues can result in preterm birth. Pro-inflammatory cytokines and pathogenic activation of toll-like receptors (TLRs) initiate a biochemical cascade of events leading to myometrial activation and contractility, cervical dilatation, and rupture of the chorioamniotic membranes. GIT2 is a signaling protein known to play a role in innate and adaptive immunity; however, its role in the inflammatory pathways of human labor is not known. In this article, we report that GIT2 expression is lower in human myometrium and fetal membranes with term labor, and in preterm amnion with histological chorioamnionitis. GIT2 knockdown by siRNA in primary myometrial and amnion cells exhibited reduced expression of pro-inflammatory cytokines and chemokines in response to inflammatory challenge by cytokines or TLR ligands. In addition, the pro-inflammatory cytokines IL1B and TNF could not induce the expression of extracellular matrix degrading enzymes in GIT2-deficient amnion cells. Myometrial activation in response to pro-inflammatory cytokines was also significantly suppressed in GIT2-deficient cells as evidenced by decreased prostaglandin release and expression of contraction-associated proteins. Further to this, collagen gel assays demonstrated that TNF had a reduced ability to induce myometrial contractility in situ in GIT2-deficient myometrial cells compared to control-transfected cells. In summary, the loss of GIT2 diminishes the effects inflammatory mediators have in promoting myometrial contraction and fetal membrane rupture in vitro, suggesting that GIT2 could be a possible target for preterm birth therapies.

Fibrinogen-Like Protein 2-Associated Transcriptional and Histopathological Features of Immunological Preeclampsia

Preeclampsia is a multifactorial hypertensive disorder of pregnancy, with variable presentation in both maternal and fetal factors, such that no treatment or marker is currently universal to all cases. Here, we demonstrate that the prothrombinase and immunomodulatory secreted factor FGL-2 (fibrinogen-like protein 2) is differentially expressed across previously characterized gene expression clusters containing clinically relevant disease subtypes. FGL2 is low in a cluster consistent with the traditional paradigm of the pathology of preeclampsia (canonical preeclampsia) and high in a cluster exhibiting evidence of immune activation (immunological preeclampsia). We show that it is part of an immunoregulatory gene module integral to the transcriptional profile and placental pathology specific to immunological preeclampsia. We determine that FGL2 associates positively with chronic inflammation lesions of the placenta while associating negatively with maternal vascular malperfusion lesions. The transcriptional profiles of maternal vascular malperfusion lesions show downregulation of FGL2 and upregulation of previously investigated preeclampsia biomarkers, such as FLT1 (Fms Related Receptor Tyrosine Kinase 1) and ENG (endoglin). Conversely, the profiles of chronic inflammation lesions show an interesting downregulation of these genes, but an upregulation of FGL2 and of FGL2-correlated immunoregulatory genes, suggesting it is upregulated downstream of major inflammatory mediators such as TNF (tumor necrosis factor)-α and IFN (interferon)-γ, hallmarks of the immunological preeclampsia subtype. This work, overall, demonstrates that FGL-2 expression levels in the term placenta reflect the unique pathophysiology that leads to immunological preeclampsia, leading to its potential as a subtype-specific biomarker.

Novel anti-inflammatory actions of TIPE2 in human primary amnion and myometrial cells

Inflammation plays a pivotal role in the terminal process of human labor and delivery, including myometrial contractions and membrane rupture. TNF-alpha-induced protein 8-like-2 (TIPE2) is a novel inflammation regulator; however, there are no studies on the role of TIPE2 in human labor. We report that in myometrium, there is decreased TIPE2 mRNA expression during late gestation which was further decreased in labor. In fetal membranes, TIPE2 mRNA expression was decreased with both term and preterm labor compared to no labor samples. Knockdown of TIPE2 by siRNA in primary myometrium and amnion cells was associated with an augmentation of IL1B and TNF-induced expression of pro-inflammatory cytokines and chemokines; expression of contraction-associated proteins and secretion of the uterotonic prostaglandin PGF2α and expression of extracellular matrix degrading enzymes. In TIPE2-deficient myometrial cells treated with inhibitors of NF-κB or ERK1/2, the secretion of pro-labor mediators was reduced back to control levels. In conclusion, these in vitro experiments indicate that loss of TIPE2 exacerbates the inflammatory response.

Targeting bromodomain-containing proteins to prevent spontaneous preterm birth

Preterm birth is a global healthcare challenge. Spontaneous preterm birth (sPTB) is commonly caused by inflammation, yet there are currently no effective therapies available. The Bromodomain and Extra-Terminal motif (BET) proteins, Bromodomain-containing protein (Brd) 2 (Brd2), Brd3 and Brd4 regulate inflammation in non-gestational tissues. The roles of Brd2-4 in human pregnancy are unknown. Using human and mouse models, the present study has identified the Brd proteins part of the process by which inflammation induces parturition. Using human clinical samples, we demonstrate that labor and infection increase the expression of Brds in the uterus and fetal membranes. In primary human myometrial, amnion and decidual cells, we found that global Brd protein inhibition, as well as selective inhibition of Brds, suppressed inflammation-induced expression of mediators involved in myometrial contractions and rupture of fetal membranes. Importantly, studies in the mouse model demonstrate that the pan-Brd inhibitor JQ1 reduced intrauterine inflammation induced by bacterial endotoxin LPS as well as decreasing the effectiveness of LPS to induce parturition. These results implicate BET proteins as novel therapeutic targets for reducing inflammation associated with spontaneous preterm labor.

Inhibition of GPR91 Reduces Inflammatory Mediators Involved in Active Labor in Myometrium

Results

GPR91 mRNA expression was significantly higher in myometrium from women during term spontaneous labor compared to no labor. Likewise, in mice, GPR91 mRNA expression was significantly upregulated in myometrium during inflammation-induced preterm labor compared to preterm no labor. In myometrial cells, IL1B and TNF significantly increased GPR91 mRNA expression. Knockdown of GPR91 by siRNA in myometrial cells significantly suppressed the secretion and/or expression of IL1B- and TNF-induced proinflammatory cytokines (GM-CSF, IL1A, IL1B, and IL6) and chemokines (CXCL8 and CCL2), myometrial contractility (expression of the contraction-associated proteins PTGFR and CX43, secretion of the uterotonic PGF_2α, and in situ collagen gel contraction), and the transcription factor NF-κB.

Conclusion

Our findings demonstrate that GPR91 is involved in the genesis of proinflammatory and prolabor mediators induced by IL1B or TNF and collectively suggest that GPR91 may contribute to augmentation of the labor processes.

Role of IRG1 in Regulating Pro-inflammatory and Pro-labor Mediators in Human Myometrium

Preterm birth is a major contributor to neonatal deaths and associated long-term morbidities for the survivors, yet therapies remain elusive, given our incomplete understanding of the mechanisms driving human labor and delivery. Human labor is an inflammatory process, and we investigated whether IRG1 (immunoresponsive gene-1) plays a role in these processes. We demonstrate that IRG1 mRNA and protein expression is significantly increased in myometrium with human term labor, compared to no labor samples, and with preterm (LPS) labor in a mouse model. Pro-labor mediators such as pro-inflammatory cytokines TNF and IL1B, and TLR ligands fsl-1, flagellin, LPS, and poly(I:C) also increased IRG1 mRNA expression in myometrial explants. IRG1 silencing, using siRNA in primary myometrial cells, displayed a decrease in the expression of inflammation-induced pro-inflammatory cytokines (IL1A, IL6), chemokines (CCL2, CXCL1, CXCL8), adhesion molecules (ICAM1, VCAM1), and contractility (PTGFR mRNA expression, prostaglandin F_2α release, and in situ gel contraction assay). Our results suggest that IRG1 is involved when pro-labor mediators activate the inflammatory processes of human labor, warranting further investigation.

Expression and function of macrophage-inducible C-type lectin (Mincle) in inflammation driven parturition in fetal membranes and myometrium

The pivotal role of inflammatory processes in human parturition is well known, but not completely understood. We have performed a study to examine the role of macrophage-inducible C-type lectin (Mincle) in inflammation-associated parturition. Using human samples, we show that spontaneous labour is associated with up-regulated Mincle expression in the myometrium and fetal membranes. Mincle expression was also increased in fetal membranes and myometrium in the presence of pro-labour mediators, the proinflammatory cytokines interleukin (IL)-1B and tumour necrosis factor (TNF), and Toll-like receptor (TLR) ligands fsl-1, poly(I:C), lipopolysaccharide (LPS) and flagellin. These clinical studies are supported by mouse studies, where an inflammatory challenge in a mouse model of preterm birth increased Mincle expression in the uterus. Importantly, elimination of Mincle decreased the effectiveness of proinflammatory cytokines and TLR ligands to induce the expression of pro-labour mediators; namely, proinflammatory cytokines and chemokines, contraction-associated proteins and prostaglandins, and extracellular matrix remodelling enzymes, matrix metalloproteinases. The data presented in this study suggest that Mincle is required when inflammatory activation precipitates parturition.

PARK7 regulates inflammation-induced pro-labour mediators in myometrial and amnion cells

Preterm birth is a prevalent cause of neonatal deaths worldwide. Inflammation has been implicated in spontaneous preterm birth involved in the processes of uterine contractility and membrane rupture. Parkinson protein 7 (PARK7) has been found to play an inflammatory role in non-gestational tissues. The aims of this study were to determine the expression of PARK7 in myometrium and fetal membranes with respect to term labour onset and to elucidate the effect of PARK7 silencing in primary myometrium and amnion cells on pro-inflammatory and pro-labour mediators. PARK7 mRNA expression was higher in term myometrium and fetal membranes from women in labour compared to non-labouring samples and in amnion from preterm deliveries with chorioamnionitis. In human primary myometrial cells transfected with PARK7 siRNA (siPARK7), there was a significant decrease in IL1B, TNF, fsl-1 and poly(I:C)-induced expression of pro-inflammatory cytokine IL6, chemokines (CXCL8, CCL2), adhesion molecule ICAM1, prostaglandin PGF_2α and its receptor PTGFR. Similarly, amnion cells transfected with siPARK7 displayed a decrease in IL1B-induced expression of IL6, CXCL8 and ICAM1. In myometrial cells transfected with siPARK7, there was a significant reduction of NF-κB RELA transcriptional activity when stimulated with fsl-1, flagellin and poly(I:C), but not with IL1B or TNF. Collectively, our novel data describe a role for PARK7 in regulating inflammation-induced pro-inflammatory and pro-labour mediators in human myometrial and amnion cells.

Placental Ras Regulates Inflammation Associated with Maternal Obesity

Heightened placental inflammation and dysfunction are commonly associated in pregnant obese women compared to their pregnant lean counterparts. The small GTPase superfamily members known as the rat sarcoma viral oncogene homolog (Ras) proteins, in particular, the K-Ras and H-Ras isoforms, have been implicated to regulate inflammation. The aims were to determine the placental Ras expression and activity with maternal obesity and its role in regulating placental inflammation. Human placenta was obtained at term Caesarean section from lean and obese pregnant women to determine the effect of maternal obesity on Ras protein expression and activity. To determine the effect of Ras on inflammation induced by bacterial endotoxin LPS and proinflammatory cytokines TNF-α or IL-1β, the chemical inhibitor lonafarnib (total Ras inhibitor) and siRNA (siKRAS and siHRAS) were used. Total Ras protein expression together with combined K-Ras and H-Ras activity was significantly increased in the placenta of obese pregnant women and when stimulated with LPS, IL-1β, or TNF-α. Lonafarnib significantly suppressed LPS-, IL-1β-, or TNF-α-induced IL-6, IL-8, MCP-1, and GRO-α expression and secretion in placental tissue. Primary trophoblast cells transfected with siKRAS or siHRAS demonstrated only K-Ras silencing significantly decreased IL-1β-, TNF-α-, or LPS-induced IL-6, IL-8, and MCP-1 expression and secretion. Furthermore, siKRAS significantly reduced downstream ERK-1/2 activation induced by LPS. In trophoblast cells, ERK-1/2 signalling is required for IL-6, IL-8, MCP-1, and GRO-α secretion. These studies implicate a role for K-Ras in regulating inflammation in human placenta. Suppressing overactive placental K-Ras function may prevent adverse fetal outcomes complicated by maternal obesity.

Identification of SMAD3 as a Novel Mediator of Inflammation in Human Myometrium In Vitro

Preterm birth remains the primary cause of early neonatal death and is a major determinant for long-term health consequences. Aberrant intrauterine inflammation and infection are known to augment the synthesis of proinflammatory cytokines and induce uterine contractions, which can subsequently lead to preterm birth. The transforming growth factor-β (TGF-β) superfamily members regulate numerous cellular processes through the activation of intracellular mediators known as mothers against decapentaplegic homolog (SMADs). Studies in nongestational tissues have shown that SMAD3 plays a role in immune regulation and inflammation; however, its role in human labour remains unknown. Thus, the present study aimed at (i) characterising the expression of SMAD3 in the human myometrium; (ii) determining the effect of bacterial and viral products and proinflammatory cytokines on SMAD3 transcriptional activity in primary human myometrial cells; and (iii) investigating the effect of SMAD3 siRNA knockdown on the production of prolabour mediators in primary human myometrial cells. Phosphorylated (i.e., active) SMAD3 protein expression was lower in the myometrium after spontaneous term labour compared to the myometrium from nonlabouring women. Using a luciferase assay, the proinflammatory cytokines IL-1β and TNF, and viral analogue polyinosinic : polycytidylic acid (poly(I : C)) significantly reduced SMAD3 transcriptional activity in human primary myometrial cells. Loss-of-function studies found that SMAD3 knockdown in myometrial cells significantly increased IL-1β- and poly(I : C)-induced proinflammatory cytokines (IL-1A, IL-6), chemokines (IL-8, MCP-1), the adhesion molecule ICAM-1, COX-2 mRNA expression, and subsequent PGF2α release. In conclusion, SMAD3 deficiency is associated with increased production of proinflammatory and prolabour mediators in the human myometrium.

Long Noncoding RNA 00473 Is Involved in Preeclampsia by LSD1 Binding-Regulated TFPI2 Transcription in Trophoblast Cells

Preeclampsia (PE) is a syndrome manifested by high blood pressure that could develop in the latter half of pregnancy; however, the underlying mechanisms are not understood. Recent evidence points to the function of noncoding RNAs (ncRNAs) as novel regulators of the invasion, migration, proliferation, and apoptosis of trophoblasts involved in the development of placental vasculature. Here, we investigated the role of long intergenic ncRNA 00473 (linc00473) in PE and the associated molecular mechanisms. The expression of linc00473 was downregulated in the placenta of patients with severe PE as revealed by qRT-PCR analysis. In vitro, linc00473 knockdown in trophoblast cell lines HTR-8/SVneo, JAR, and JEG3 significantly inhibited cell proliferation and promoted apoptosis, whereas linc00473 overexpression stimulated trophoblast proliferation. The mechanistic insights were provided by RNA-seq and qRT-PCR, which revealed that linc00473 could regulate the transcription of genes relevant to cell growth, migration, and apoptosis. In particular, linc00473 inhibited the expression of tissue factor pathway inhibitor 2 (TFPI2) through binding to lysine-specific demethylase 1 (LSD1). These results indicate that linc00473 could be involved in the pathogenesis and development of PE and may be a candidate biomarker as well as therapeutic target for this disease.

SMAD7 regulates proinflammatory and prolabor mediators in amnion and myometrium

Preterm birth continues to be a significant public health problem. Infection (bacterial and or viral) and inflammation, by stimulating proinflammatory cytokines, adhesion molecules, and matrix metalloproteinase 9 (MMP9), play a central role in the rupture of membranes and myometrial contractions. SMAD7 has been implicated in regulating the inflammatory response; however, no studies have been performed with regard to human labor. In this study, we determined the effect of spontaneous human labor and prolabor mediators on SMAD7 expression in myometrium and fetal membranes. Functional studies were employed to investigate the effect of siRNA knockdown of SMAD7 (siSMAD7) in regulating infection and inflammation-induced prolabor mediators. SMAD7 mRNA and protein expression were significantly higher with spontaneous term labor, compared to no labor, in myometrium and fetal membranes. SMAD7 expression was also significantly higher in amnion from women with preterm chorioamnionitis. The proinflammatory cytokines IL1B and TNF, the bacterial product fsl-1, and the viral dsRNA analog poly(I:C) significantly increased SMAD7 in myometrial cells and amnion cells. In myometrial cells, siSMAD7 cells significantly decreased cytokine (IL6) and chemokine (CXCL1, CXCL8, CCL2 are also known as GRO-alpha, interleukin (IL)-8 and monocyte chemotactic protein-1 (MCP-1)) production induced by IL1B, TNF, and fsl-1. There was also a decrease in the expression of adhesion molecules intercellular adhesion molecule 1 (ICAM1) and vascular cell adhesion molecule 1 (VCAM1) in siSMAD7 cells, and MMP9 expression. In amnion, siSMAD7 cells treated with IL1B also decreased cytokine and chemokine production, ICAM1 and MMP9 expression. In conclusion, we report a proinflammatory role for SMAD7 in human gestational tissues, with SMAD7 silencing attenuating the inflammatory response.

A20, an essential component of the ubiquitin-editing protein complex, is a negative regulator of inflammation in human myometrium and foetal membranes

STUDY QUESTION

Does A20 regulate mediators involved in the terminal processes of human labour in primary myometrial and amnion cells?

SUMMARY ANSWER

A20 is a nuclear factor-kappa B (NF-κB) responsive gene that acts as a negative regulator of NF-κB-induced expression of pro-labour mediators.

WHAT IS KNOWN ALREADY

Inflammation is commonly implicated in spontaneous preterm birth and the processes involved in rupture of foetal membranes and uterine contractions. In myometrium and foetal membranes, the pro-inflammatory transcription factor NF-κB regulates the transcription of pro-labour mediators in response to inflammatory stimuli. In non-gestational tissues, A20 is widely recognised as an anti-inflammatory protein that inhibits inflammation-induced NF-κB signalling.

STUDY DESIGN, SIZE, DURATION

Primary human amnion and myometrial cells were used to determine the effect of pro-inflammatory mediators on A20 expression and the effect of A20 siRNA on the expression and secretion of pro-labour mediators. The expression of A20 was assessed in myometrium and foetal membranes from non-labouring and labouring women at preterm and or term (n = 8 or nine samples per group).

PARTICIPANTS/MATERIALS, SETTING, METHODS

The effects of pro-inflammatory mediators and of A20 siRNA in cell cultures were determined by quantitative RT-PCR (qRT-PCR), western blots, immunoassays, gelatin zymography and luciferase assays. A20 expression in tissue samples was assessed by qRT-PCR. Statistical significance was ascribed to a P value < 0.05.

MAIN RESULTS AND THE ROLE OF CHANCE

In primary cells isolated from myometrium and or amnion, the pro-inflammatory cytokines IL1B and TNF, the bacterial products flagellin and fsl-1, and the viral double stranded RNA analogue poly(I:C) significantly increased A20 mRNA expression via NF-κB. A20 siRNA studies in primary myometrial and amnion cells demonstrated an augmentation of inflammation-induced expression and or secretion of pro-inflammatory cytokines (IL1A, IL6), chemokines (CXCL1, CXCL8, CCL2), adhesion molecules (ICAM1, VCAM1), contraction-associated proteins (PTGS2, PTGFR, PGF2α) and the extracellular matrix degrading enzyme MMP9, as well as NF-κB activation. Inhibition of NF-κB activity significant attenuated inflammation-induced expression of pro-labour mediators in A20 siRNA transfected cells. Finally, A20 mRNA expression was decreased in myometrium and foetal membranes with labour, and in foetal membranes with chorioamnionitis.

LARGE SCALE DATA

Not applicable.

LIMITATIONS, REASONS FOR CAUTION

The conclusions of this study are solely reliant on the data from in vitro experiments using cells isolated from myometrium and amnion.

WIDER IMPLICATIONS OF THE FINDINGS

The results of this study raise the possibility that targeting A20 may be a therapeutic approach to reduce inflammation associated with spontaneous preterm birth.

STUDY FUNDING AND COMPETING INTEREST(S)

Associate Professor Martha Lappas is supported by a Career Development Fellowship from the National Health and Medical Research Council (NHMRC; grant no. 1047025). Funding for this study was provided by the NHMRC (grant no. 1058786), Norman Beischer Medical Research Foundation and the Mercy Research Foundation. There are no competing interests.

Pellino 1 is a novel regulator of TNF and TLR signalling in human myometrial and amnion cells

Preterm birth is the primary cause of neonatal deaths and morbidities. Pathological processes causally linked to preterm birth are inflammation and infection. Pellino-1 (Peli1) has previously been found to regulate the inflammatory response in non-gestational tissues in response to toll-like receptor (TLR) ligands and pro-inflammatory cytokines. The aims of this study were to determine the effect of labor on Peli1 expression in myometrium and fetal membranes, and the effect of Peli1 silencing by siRNA (siPELI1) on the production of pro-inflammatory and pro-labor mediators. The expression of Peli1 was found to be higher in myometrium and fetal membranes with term labor, compared to non-laboring samples. Peli1 mRNA and protein expression was also higher in amnion from women with preterm histological chorioamnionitis. In human primary myometrial cells, siPELI1 transfected cells showed a decrease in pro-inflammatory cytokine IL6, chemokines (CXCL8, CCL2) and adhesion molecule ICAM1 when in the presence of pro-inflammatory cytokine TNF, TLR2/6 ligand fsl-1, TLR5 ligand flagellin, and TLR3 ligand poly(I:C). Similarly in primary amnion cells, siPELI1 transfected cells decreased IL1B-induced expression and secretion of IL6 and CXCL8. In siPELI1 transfected myometrial cells, there was a decrease in prostaglandin PGF_2α and its receptor, PTGFR mRNA expression when treated with TNF. There was a decrease in NF-κB RELA transcriptional activity in siPELI1 transfected cells in the presence of TNF, fsl-1 and flagellin, but not poly(I:C). Our study suggests a novel role for Peli1 in regulating pro-inflammatory and pro-labor mediators through TNF and TLR signalling.

Inhibition of PIM1 kinase attenuates inflammation-induced pro-labour mediators in human foetal membranes in vitro

STUDY QUESTION

Does proviral integration site for Moloney murine leukaemic virus (PIM)1 kinase play a role in regulating the inflammatory processes of human labour and delivery?

SUMMARY ANSWER

PIM1 kinase plays a critical role in foetal membranes in regulating pro-inflammatory and pro-labour mediators.

WHAT IS KNOWN ALREADY

Infection and inflammation have strong causal links to preterm delivery by stimulating pro-inflammatory cytokines and collagen degrading enzymes, which can lead to rupture of membranes. PIM1 has been shown to have a role in immune regulation and inflammation in non-gestational tissues; however, its role has not been explored in the field of human labour.

STUDY DESIGN, SIZE, DURATION

PIM1 expression was analysed in myometrium and/or foetal membranes obtained at term and preterm (n = 8-9 patients per group). Foetal membranes, freshly isolated amnion cells and primary myometrial cells were used to investigate the effect of PIM1 inhibition on pro-labour mediators (n = 5 patients per treatment group).

PARTICIPANTS/MATERIALS, SETTING AND METHODS

Foetal membranes, from term and preterm, were obtained from non-labouring and labouring women, and from preterm pre-labour rupture of membranes (PPROM) (n = 9 per group). Amnion was collected from women with and without preterm chorioamnionitis (n = 8 per group). Expression of PIM1 kinase was determined by qRT-PCR and western blotting. To determine the effect of PIM1 kinase inhibition on the expression of pro-inflammatory and pro-labour mediators induced by bacterial products lipopolysaccharide (LPS) (10 μg/ml) and flagellin (1 μg/ml) and pro-inflammatory cytokine tumour necrosis factor (TNF) (10 ng/ml), chemical inhibitors SMI-4a (20 μM) and AZD1208 (50 μM) were used in foetal membrane explants and siRNA against PIM1 was used in primary amnion cells. Statistical significance was set at P < 0.05.

MAIN RESULTS AND THE ROLE OF CHANCE

PIM1 expression was significantly increased in foetal membranes after spontaneous term labour compared to no labour at term and in amnion with preterm chorioamnionitis compared to preterm with no chorioamnionitis. There was no change in PIM1 expression with preterm labour or PPROM compared to preterm with no labour or PPROM. In human foetal membranes, PIM1 inhibitors SMI-4a and AZD1208 significantly decreased the expression of pro-inflammatory cytokine interleukin-6 (IL6) and chemokines CXCL8 and CCL2 mRNA and release, prostaglandin prostaglandin F2α (PGF2α) release, adhesion molecule intercellular adhesion molecule 1 mRNA expression and release, and oxidative stress marker 8-isoprostane release after stimulation with either LPS or flagellin. Primary amnion cells transfected with PIM1 siRNA also showed decreased expression of IL6, CXCL8 and CCL2, PTGS2 mRNA and PGF2α release, and matrix metalloproteinase-9 (MMP9) expression, when stimulated with TNF.

LARGE SCALE DATA

None.

LIMITATIONS, REASONS FOR CAUTION

The conclusions were drawn from in vitro experiments using foetal membrane explants and primary cells isolated from amnion. Animal models are necessary to determine whether PIM1 kinase inhibitors can prevent spontaneous preterm birth in vivo.

WIDER IMPLICATIONS OF THE FINDINGS

PIM1 kinase inhibitors may provide a novel therapeutic approach for preventing spontaneous preterm birth.

STUDY FUNDING/COMPETING INTEREST(S)

Associate Professor Martha Lappas is supported by a Career Development Fellowship from the National Health and Medical Research Council (NHMRC; grant no. 1047025). Funding for this study was provided by the NHMRC (grant no. 1058786), Norman Beischer Medical Research Foundation and the Mercy Research Foundation. The authors have no conflict of interest.

DREAM Is Involved in the Genesis of Inflammation-Induced Prolabour Mediators in Human Myometrial and Amnion Cells

Preterm birth is the primary cause of perinatal morbidity and mortality worldwide. Inflammation induces a cascade of events leading to preterm birth by activating nuclear factor-κB (NF-κB). In nongestational tissues, downstream regulatory element antagonist modulator (DREAM) regulates NF-κB activity. Our aims were to analyse DREAM expression in myometrium and fetal membranes obtained at term and preterm and to determine the effect of DREAM inhibition on prolabour mediators in primary myometrial and amnion cells. DREAM mRNA expression was significantly higher in fetal membranes obtained after spontaneous labour compared to nonlabour and in amnion from women with histological preterm chorioamnionitis when compared to amnion from women without chorioamnionitis. In primary myometrial and amnion cells, the effect of DREAM silencing by siRNA was a significant decrease in the expression of proinflammatory cytokine IL-6, the chemokines IL-8 and MCP-1, the adhesion molecule ICAM-1, MMP-9 mRNA expression and activity, and NF-κB transcriptional activity when stimulated with the proinflammatory cytokine IL-1β, the bacterial products fsl-1 or flagellin, or the viral dsRNA analogue poly(I:C). These data suggest that, in states of heightened inflammation, DREAM mRNA expression is increased and that, in myometrial and amnion cells, DREAM regulates proinflammatory and prolabour mediators which may be mediated via NF-κB.

The IL-1β signalling pathway and its role in regulating pro-inflammatory and pro-labour mediators in human primary myometrial cells

Interleukin (IL)-1β plays a central role in the processes of human labour and delivery. The adaptor proteins involved in the IL-1β signalling pathway in human myometrium are not known. This study sought to determine the role of the adaptor proteins myeloid differentiation primary response 88 (MyD88), tumour necrosis factor receptor-associated factor 6 (TRAF6), IL-1 receptor-associated kinase 4 (IRAK4) and transforming growth factor beta-activated kinase 1 (TAK1) in IL-1β-induced formation of pro-inflammatory and pro-labour mediators in human myometrium. Human primary myometrial cells were transfected with siRNA against MyD88 (siMYD88), TRAF6 (siTRAF6), IRAK4 (siIRAK4) or TAK1 (siTAK1), treated with IL-1β, and assayed for the mRNA expression and or secretion of pro-inflammatory and pro-labour mediators. Transfection of primary myometrial cells with siMYD88, siTRAF6, siIRAK4 and siTAK1 significantly decreased IL-1β-induced IL-1α, IL-6, growth-regulated alpha protein (GRO-α), IL-8, monocyte chemoattractant protein (MCP)-1, intercellular adhesion molecule (ICAM)-1 and cyclooxygenase (COX)-2 mRNA expression and release of IL-6, GRO-α, IL-8, MCP-1, ICAM-1 and prostaglandin PGF_2α. The expression and secretion of the extracellular matrix remodelling enzyme matrix metalloproteinase (MMP)-9 was significantly lower with siMYD88 and siTRAF6. Finally, IL-1β-induced nuclear factor κB (NF-κB) transcriptional activity was significantly attenuated by transfection with siMyD88, siTRAF6 and siIRAK4; there was no effect of siTAK1 transfection on NF-κB transcriptional activity. Collectively, these findings suggest that MyD88, TRAF6, IRAK4 and TAK1 are involved in IL-1β signalling in human myometrium. Further studies are required to determine if inhibition of these proteins can prevent preterm birth.

TRADD, TRAF2, RIP1 and TAK1 are required for TNF-α-induced pro-labour mediators in human primary myometrial cells

PROBLEM

TNF-α plays a central role in the processes of human labour and delivery. This study sought to determine the role of the adaptor proteins TNFR1-associated death domain protein (TRADD), TNF receptor-associated factor 2 (TRAF2), receptor interacting protein 1 (RIP1) and transforming growth factor beta-activated kinase 1 (TAK1) in TNF-α-induced formation of pro-labour mediators.

METHOD OF STUDY

Human primary myometrial cells were transfected with siRNA against TRADD (siTRADD), TRAF2 (siTRAF2), RIP1 (siRIP1) or TAK1 (siTAK1), treated with TNF-α, and assayed for pro-inflammatory mediators expression.

RESULTS

siTRADD, siTRAF2, siRIP1 and siTAK1 significantly decreased TNF-α-induced IL-1α, IL-1β, IL-6, IL-8, MCP-1 mRNA expression and release of IL-6, IL-8 and MCP-1; and cyclooxygenase (COX)-2 expression and release of prostaglandin PGF_2α . There was a significant attenuation of TNF-α-induced expression of adhesion molecules ICAM-1 and VCAM-1 mRNA with siTRADD, siTRAF2 or siRIP1. siTRADD and siRIP1 significantly attenuated TNF-α-induced MMP-9 mRNA expression and release and nuclear factor κB (NF-κB) transcriptional activity. There was a significant increase in TNF-α-induced sVCAM-1 release, MMP-9 mRNA expression and NF-κB activity with siTAK1.

CONCLUSION

TRADD, TRAF2, RIP1 and TAK1 are involved in TNF-α signalling in human myometrium. Further studies are required to determine whether inhibition of these proteins can prevent preterm birth.

The Adaptor Protein p62 Mediates Nuclear Factor κB Activation in Response to Inflammation and Facilitates the Formation of Prolabor Mediators in Human Myometrium

Preventing spontaneous preterm birth is one of the most important issues facing perinatal medicine today. The pathophysiology of preterm labor, the single biggest cause of preterm birth, is poorly understood. Inflammation, however, plays a significant role in the terminal processes of human labor, which include myometrial contractions. Nuclear factor κB (NF-κB) drives the transcription of proinflammatory mediators involved in the terminal effector pathways of human labor and delivery. Recent studies in nongestational tissues have shown that the adaptor protein p62 interacts with NF-κB to induce inflammation. The aim of this study was to determine the role of p62 in the genesis of NF-κB-induced proinflammatory and prolabur mediators. Human spontaneous term labor was associated with increased p62 messenger RNA (mRNA) and protein expression in myometrium. Myometrial cells treated with proinflammatory cytokines interleukin 1β (IL-1β) and tumor necrosis factor alpha (TNF-α) also significantly increased p62 mRNA and protein expression. Functional studies using p62 small interfering RNA (siRNA) demonstrated a significant attenuation of TNF-α- and IL-1β-induced proinflammatory cytokines (IL-6) and chemokine (IL-8 and monocyte chemoattractant protein 1 [MCP-1]) mRNA expression and secretion, expression of cyclooxygenase 2, release of prostaglandin F_2α (PGF_2α), and expression of the prostaglandin F receptor (FP). In addition, siRNA knockdown of p62 significantly suppressed IL-1β- and TNF-α-induced NF-κB activation. Collectively, these studies suggest that p62 is involved in the genesis of NF-κB-induced proinflammatory and prolabor mediators.

Optineurin suppression activates the mediators involved in the terminal effector pathways of human labour and delivery

Spontaneous preterm birth remains the major cause of neonatal death and morbidity. Studies in non-gestational tissues report that optineurin (OPTN) is critical in the termination of NFKB1 activity and control of inflammation, central features of spontaneous preterm birth. The aims of the present study were to determine: (1) OPTN expression in fetal membranes and the myometrium during labour; (2) the effects of IL1B on OPTN expression in primary myometrial cells; and (3) the effects of OPTN short interference (si) RNA on IL1B-stimulated proinflammatory and prolabour mediators. OPTN mRNA and protein expression was significantly decreased with spontaneous term labour in fetal membranes and the myometrium. Although there was no effect of spontaneous preterm labour on OPTN expression in fetal membranes, there was decreased OPTN expression in membranes with chorioamnionitis and myometrial cells treated with 1ng mL^-1 IL1B for 1 or 6h. In cells transfected with OPTN siRNA, significant increases were seen in IL1B-stimulated IL6, tumour necrosis factor, CXCL8 and monocyte chemoattractant protein-1 mRNA expression and release, cyclo-oxygenase-2 and prostanoid PTGFR receptor mRNA expression and the release of prostaglandin F_2α. There was no change in IL1B-stimulated NFKBIA expression; however, there was increased NFKB1 p65 DNA-binding activity. The results of the present study suggest that OPTN is a negative regulator of inflammation-induced prolabour mediators.

RAF1 is increased in labouring myometrium and modulates inflammation-induced pro-labour mediators

Inflammation plays a central role in the terminal process of human labour and delivery, including myometrial contractions. RAF1 proto-oncogene serine/threonine-protein kinase (RAF1) can activate ERK (official gene symbolMAPK1) and/or nuclear factor-kappa B (NF-κB) to regulate genes involved in inflammation. There are, however, no studies on the role of RAF1 in the processes of human labour and delivery. Thus, the aims of this study were to determine the effect of i) human labour and pro-inflammatory cytokines interleukin 1 beta (IL1B) and tumour necrosis factor (TNF) alpha on RAF1 protein expression in myometrium and ii) siRNA knockdown ofRAF1on pro-inflammatory and pro-labour mediators in human myometrial primary cells. Term labour was associated with an increase in RAF1 protein expression. Furthermore, RAF1 protein expression was increased in myometrial cells treated with IL1B and TNF, two likely factors contributing to preterm birth. Knockdown ofRAF1by siRNA in primary myometrial cells significantly decreased IL1B- and TNF-inducedIL1A, IL1B, IL6,(C-X-C motif) ligand 8 (CXCL8)and chemokine (C-C motif) ligand 2 (CCL2) mRNA abundance and IL6, IL8 and CCL2; prostaglandin-endoperoxide synthase 2 (PTGS2) mRNA levels and prostaglandin PGF2αrelease; and NF-κB activation. Furthermore,RAF1knockdown was associated with decreased activation of ERK in the presence of IL1B but not TNF. Concordantly, the ERK inhibitor U0126 significantly decreased IL1B-inducedIL6,CXCL8,CCL2andPTGS2mRNA abundance; IL6, CXCL8, CCL2 and PGF2αrelease; and NF-κB activation. In conclusion, IL1B induces the expression and secretion of pro-labour mediators through the RAF1–MAPK1–NF-κB signalling pathway. TNF, on the other hand, regulates pro-labour mediators through the RAF1–NF-κB signalling pathway via an MAPK1-independent mechanism.

Scrutinising the regulators of syncytialization and their expression in pregnancy-related conditions

The placenta is important for the success of gestation and foetal development. In fact, this specialized pregnancy organ is essential for foetal nourishment, support, and protection. In the placenta, there are different cell populations, including four subtypes of trophoblasts. Cytotrophoblasts fuse and differentiate into the multinucleated syncytiotrophoblast (syncytialization). Syncytialization is a hallmark of placentation and is highly regulated by numerous molecules with distinct roles. Placentas from pregnancies complicated by preeclampsia, intrauterine growth restriction or trisomy 21 have been associated with a defective syncytialization and an altered expression of its modulators. This work proposes to review the molecules that promote or inhibit both fusion and biochemical differentiation of cytotrophoblasts. Moreover, it will also analyse the syncytialization modulators abnormally expressed in pathological placentas, highlighting the molecules that may contribute to the aetiology of these diseases.

Copper metabolism domain-containing 1 represses the mediators involved in the terminal effector pathways of human labour and delivery

STUDY HYPOTHESIS

Does Copper Metabolism MURR1 Domain 1 (COMMD1) play a role in regulating the mediators involved in the terminal processes of human labour and delivery?

STUDY FINDING

COMMD1 plays a critical role in the termination of nuclear factor-κB (NF-κB) activity and the control of pro-inflammatory and pro-labour mediators.

WHAT IS KNOWN ALREADY

Inflammation and infection are the biggest aetiological factors associated with preterm birth. NF-κB drives the transcription of pro-inflammatory mediators involved in the terminal effector pathways of human labour and delivery. In non-gestational tissues, COMMD1 is a negative regulator of NF-κB-induced inflammation.

STUDY DESIGN, SAMPLES/MATERIALS, METHODS

The mRNA and/or protein level of COMMD1 was assessed in myometrium (n = 8 per group) and fetal membranes (n = 8 per group) obtained from term non-labouring and labouring women at term, and fetal membranes (n = 8 per group) at preterm with and without histological chorioamnionitis. Primary human myometrial cells were used to determine the effect of pro-inflammatory mediators on COMMD1 level, and the effect of COMMD1 small interfering RNA (siRNA) on pro-labour mediators. Statistical significance was ascribed to a P < 0.05.

MAIN RESULTS AND THE ROLE OF CHANCE

COMMD1 expression was significantly decreased with spontaneous term labour in myometrium; in fetal membranes with histologically confirmed chorioamnionitis and in myometrial cells treated with pro-inflammatory cytokines interleukin (IL)-1β and tumour necrosis factor (TNF)-α, the bacterial product fibroblast-stimulating lipopeptide and the viral double stranded RNA analogue polyinosinic polycytidilic acid. Loss-of-function studies revealed an increase in inflammation- and infection-induced TNF-α, IL-1α, IL-1β, IL-6, IL-8 and/or monocyte chemoattractant protein-1 mRNA abundance and/or release; and cyclo-oxygenase-2 mRNA level, release of prostaglandin (PG) F2α and mRNA level of the PGF2α receptor FP. In addition, siRNA knockdown of COMMD1 was associated with significantly increased NF-κB activation as evidenced by increased IL-1β-induced IκB-α protein degradation and NF-κB DNA binding activity.

LIMITATIONS, REASONS FOR CAUTION

The conclusions are based on in vitro experiments with cells isolated from myometrium. Animal models, however, will be required to establish whether COMMD1 activators can prevent spontaneous preterm birth in vivo.

WIDER IMPLICATIONS OF THE FINDINGS

The control of COMMD1 activation may provide an alternative therapeutic strategy for reducing the release of pro-labour mediators in spontaneous preterm labour.

LARGE SCALE DATA

Not applicable.

STUDY FUNDING AND COMPETING INTERESTS

Associate Professor Martha Lappas is supported by a Career Development Fellowship from the National Health and Medical Research Council (NHMRC; grant no. 1047025). Additional funding was provided by the Medical Research Foundation for Women and Babies and the Mercy Research Foundation. The author has no conflict of interest.

Maternal Prenatal Mental Health and Placental 11β-HSD2 Gene Expression: Initial Findings from the Mercy Pregnancy and Emotional Wellbeing Study

High intrauterine cortisol exposure can inhibit fetal growth and have programming effects for the child's subsequent stress reactivity. Placental 11beta-hydroxysteroid dehydrogenase (11β-HSD2) limits the amount of maternal cortisol transferred to the fetus. However, the relationship between maternal psychopathology and 11β-HSD2 remains poorly defined. This study examined the effect of maternal depressive disorder, antidepressant use and symptoms of depression and anxiety in pregnancy on placental 11β-HSD2 gene (HSD11B2) expression. Drawing on data from the Mercy Pregnancy and Emotional Wellbeing Study, placental HSD11B2 expression was compared among 33 pregnant women, who were selected based on membership of three groups; depressed (untreated), taking antidepressants and controls. Furthermore, associations between placental HSD11B2 and scores on the State-Trait Anxiety Inventory (STAI) and Edinburgh Postnatal Depression Scale (EPDS) during 12-18 and 28-34 weeks gestation were examined. Findings revealed negative correlations between HSD11B2 and both the EPDS and STAI (r = -0.11 to -0.28), with associations being particularly prominent during late gestation. Depressed and antidepressant exposed groups also displayed markedly lower placental HSD11B2 expression levels than controls. These findings suggest that maternal depression and anxiety may impact on fetal programming by down-regulating HSD11B2, and antidepressant treatment alone is unlikely to protect against this effect.

Predictive Value of Free β-hCG Multiple of the Median for Women with Preeclampsia

BACKGROUND

Preeclampsia (PE) is relatively common and is unpredictable in its onset and progression.

AIMS

We investigated the clinical value of using the multiple of the median (MoM) of free β-human chorionic gonadotropin (β-hCG) concentrations in women with normal pregnancy and PE.

METHODS

This study was based on a dataset available from published studies, and the relevant studies were retrieved from multiple electronic databases. Data were extracted from case-control studies; a random-effects model was employed, and standardized mean difference and 95% confidence intervals were calculated. Twelve case-control studies (eleven English-based articles and one Chinese-based article) were analyzed in the current meta-analysis and included 702 patients with PE and 8,233 women with normal pregnancies.

RESULTS

Statistical analysis revealed a higher MoM of β-hCG serum levels in patients with PE. Ethnicity subgroup analysis showed that the MoM of serum β-hCG levels was significantly higher in women with PE in both Asian and Caucasian populations.

CONCLUSION

The MoM of β-hCG serum levels was significantly increased in women with PE compared to women with normal pregnancies. Screening for serum β-hCG MoM levels will be helpful in the early identification of pregnancies at risk of developing PE. © 2015 S. Karger AG, Basel.

A novel role for GSK3 in the regulation of the processes of human labour

Preterm birth remains the largest single cause of neonatal death and morbidity. Infection and/or inflammation are strongly associated with preterm delivery. Glycogen synthase kinase 3 (GSK3) is known to be a crucial mediator of inflammation homeostasis. The aims of this study were to determine the effect of spontaneous human labour in foetal membranes and myometrium on GSK3α/β expression, and the effect of inhibition of GSK3α/β on pro-labour mediators in foetal membranes and myometrium stimulated with Toll-like receptor (TLR) ligands and pro-inflammatory cytokines. Term and preterm labour in foetal membranes was associated with significantly decreased serine phosphorylated GSK3α and β expression, and thus increased GSK3 activity. There was no effect of term labour on serine phosphorylated GSK3β expression in myometrium. The specific GSK3α/β inhibitor CHIR99021 significantly decreased lipopolysaccharide (ligand to TLR4)-stimulated pro-inflammatory cytokine gene expression and release;COX2gene expression and prostaglandin release; andMMP9gene expression and pro MMP9 release in foetal membranes and/or myometrium. CHIR99021 also decreased FSL1 (TLR2 ligand) and flagellin (TLR5 ligand)-induced pro-inflammatory cytokine gene expression and release andCOX2mRNA expression and prostaglandin release.GSK3βsiRNA knockdown in primary myometrial cells was associated with a significant decrease in IL1β and TNFα-induced pro-inflammatory cytokine and prostaglandin release. In conclusion, GSK3α/β activity is increased in foetal membranes after term and preterm labour. Pharmacological blockade of the kinase GSK3 markedly reduced pro-inflammatory and pro-labour mediators in human foetal membranes and myometrium, providing a possible therapeutics for the management of preterm labour.

Activation of AMPK in human fetal membranes alleviates infection-induced expression of pro-inflammatory and pro-labour mediators

INTRODUCTION

In non-gestational tissues, the activation of adenosine monophosphate (AMP)-activated kinase (AMPK) is associated with potent anti-inflammatory actions. Infection and/or inflammation, by stimulating pro-inflammatory cytokines and matrix metalloproteinase (MMP)-9, play a central role in the rupture of fetal membranes. However, no studies have examined the role of AMPK in human labour.

METHODS

Fetal membranes, from term and preterm, were obtained from non-labouring and labouring women, and after preterm pre-labour rupture of membranes (PPROM). AMPK activity was assessed by Western blotting of phosphorylated AMPK expression. To determine the effect of AMPK activators on pro-inflammatory cytokines, fetal membranes were pre-treated with AMPK activators then stimulated with bacterial products LPS and flagellin or viral dsDNA analogue poly(I:C). Primary amnion cells were used to determine the effect of AMPK activators on IL-1β-stimulated MMP-9 expression.

RESULTS

AMPK activity was decreased with term labour. There was no effect of preterm labour. AMPK activity was also decreased in preterm fetal membranes, in the absence of labour, with PROM compared to intact membranes. AMPK activators AICAR, phenformin and A769662 significantly decreased IL-6 and IL-8 stimulated by LPS, flagellin and poly(I:C). Primary amnion cells treated with AMPK activators significantly decreased IL-1β-induced MMP-9 expression.

DISCUSSION

The decrease in AMPK activity in fetal membranes after spontaneous term labour and PPROM indicates an anti-inflammatory role for AMPK in human labour and delivery. The use of AMPK activators as possible therapeutics for threatened preterm labour would be an exciting future avenue of research.

Slit2 exerts anti-inflammatory actions in human placenta and is decreased with maternal obesity

PROBLEM

Obese pregnancies are characterised by increased inflammation. Members of the Slit/Roundabout (Robo) family are key regulators of the inflammatory response. The aim of this study was to determine the effect of (i) pre-existing maternal obesity on Slit-Robo expression in human placenta and (ii) Slit2 knockdown by siRNA in primary trophoblast cells on markers of inflammation.

METHOD OF STUDY

The expression of Slit-Robo protiens was assessed in human placenta from lean (n = 15) and obese (n = 16) patients by qRT-PCR and Western blotting. Primary trophoblast cells were used to determine the effect of pro-inflammatory mediators on Slit2 expression, and the effect of Slit2 siRNA on pro-inflammatory mediators.

RESULTS

While there was no change in Slit3, Robo1 or Robo4 expression, Slit2 expression was significantly lower in obese placenta compared to lean placenta. Human primary trophoblast cells treated with pro-inflammatory mediators IL-1β, TNF-α and LPS significantly decreased Slit2 expression. Slit2 silencing by siRNA augmented IL-6 expression and secretion in cells stimulated with TNF-α, LPS and TNF-α; IL-8 gene expression and/or release in cells stimulated with IL-1β and LPS; TNF-α gene expression and secretion in cells stimulated with LPS; and MMP-9 gene expression and pro MMP-9 levels in cells stimulated with TNF-α.

CONCLUSION

The anti-inflammatory effects of Slit2 in human placenta is a novel finding, and suggests that inflammatory mediators, which are increased with obesity, downregulates Slit2 to enhance placental inflammation. Given the central role of pro-inflammatory cytokines in placental nutrient transport, our findings suggest Slit2 may play a role in fetal growth and development.