Activation of villous trophoblastic p38 and ERK1/2 signaling pathways in preterm preeclampsia and HELLP syndrome

Establishment of a placental lncRNA-mRNA expression network for early-onset preeclampsia

BACKGROUND

This study aimed to establish a placental long non-coding RNA (lncRNA)-mRNA expression network for early-onset preeclampsia (early-onset PE).

METHODS

The RNA sequencing data of the GSE14821 dataset were acquired. Several crucial lncRNAs and mRNAs were exerted based on the differential expression analysis of lncRNA and mRNA. By analyzing the differentially expressed lncRNA and mRNA, we constructed a regulatory network to explore the mechanism of the lncRNA in early onset preeclampsia.

RESULTS

A total of 4436 differentially expressed lncRNAs (DElncRNAs) were identified in early-onset PE placenta samples compared with control placenta samples. Pearson correlation analysis revealed significant correlations between 3659 DElncRNAs and 372 DEmRNAs. KEGG analysis showed that the DEmRNAs were enriched in cytokine-cytokine receptor and hypoxia-inducible factor (HIF)-1 pathways. Several well-known early-onset PE-related mRNAs, such as vascular endothelial growth factor A (VEGFA) and VEGF receptor 1 (FLT1), were involved in the two pathways. Weighted gene co-expression network analysis and cis-regulatory analysis further suggested the involvement of the two pathways and potential DElncRNA-DEmRNA interactions in early-onset PE. Moreover, the upregulation of representative DElncRNAs, such as RP11-211G3.3 and RP11-65J21.3, and DEmRNAs, such as VEGFA and FLT1, were validated in clinical placenta samples from patients with early-onset PE by quantitative reverse transcription PCR. Importantly, overexpression of RP11-65J21.3 significantly promoted the proliferation of HTR-8 trophoblast cells at 72 h after transfection.

CONCLUSIONS

In conclusion, we identified placental DElncRNAs of early-onset PE and established a DElncRNA-DEmRNA network that was closely related to the cytokine-cytokine receptor and HIF-1 pathways. Our results provide potential diagnostic markers and therapeutic targets for early-onset PE management.

Value of proteinuria in evaluating the severity of HELLP and its maternal and neonatal outcomes

BACKGROUND

HELLP syndrome refers to a group of clinical syndromes characterized by hemolysis, elevated liver enzymes and low platelet, and the evidence on the association between proteinuria and the severity of HELLP and its maternal and neonatal outcomes is rare.

METHODS

106 pregnant women were assigned to the proteinuric group (24-hUPro ≥ 0.3 g, 79 cases) and the non-proteinuric group (24-hUPro < 0.3 g, 27 cases). The proteinuric group was further divided into three subgroups: mild group (24-hUPro:0.3-2.0 g, 33 cases), moderate group (24-hUPro:2.0-5.0 g, 21 cases) and severe group (24-hUPro: ≥5.0 g, 25 cases). The general clinical data, laboratory indexes, complications and pregnancy outcome and adverse neonatal outcomes of HELLP with or without proteinuric were analyzed.

RESULTS

Compared with proteinuric group, the non-albuminuric group or in the three proteinuric subgroups of HELLP pregnant women's, increased proteinuria was associated with earlier onset gestations, higher incidence of abdominal pain, skin jaundice, headache, blurred vision (p < 0.05 respectively), and also the higher levels of ALT, AST, LDH, Fib, APTT, ATII, proportions of tubular urine and lower levels of ALB, PLT (p < 0.05 respectively). In the three subgroups of the proteinuric group, the ratio of fetal growth restriction, cesarean section and postpartum hemorrhage were compared, and the difference was statistically significant (p < 0.05 respectively). Compared with the proteinuric group, the non-proteinuric group had higher birth weight, birth length, and lower SGA, admission rate in NICU (p < 0.05 respectively). In the three subgroups of the proteinuric group, significant differences were identified in the adverse outcomes of newborns (p < 0.05 respectively), and the incidence of adverse outcomes in neonates tended to be higher. Significant differences were identified in birth weight, birth length, and lower SGA and NICU occupancy rate among the three subgroups (p < 0.05 respectively).

CONCLUSIONS

HELLP syndrome is a severe complication of pregnancy, involving multiple systems of the whole body. It has posed a great challenge to obstetricians for its acute onset, dangerous condition, rapid progress, and great harm. Thus, insights into HELLP syndrome should be gained, and early diagnosis, early treatment and timely termination of pregnancy should be conducted to reduce the incidence of maternal and fetal adverse outcomes and improve maternal and fetal prognosis.

miR-101-5p suppresses trophoblast cell migration and invasion via modulating the DUSP6-ERK1/2 axis in preeclampsia

PURPOSE

Dysregulated behaviors of trophoblast cells leading to defective placentation are considered the main cause of preeclampsia (PE). Abnormal miRNA expression profiles have been observed in PE placental tissue, indicating the significant role of miRNAs in PE development. This study aimed to investigate the expression of miR-101-5p in PE placental tissue and its biological functions.

METHODS

The expression of miR-101-5p in placental tissue was detected by quantitative real-time PCR (qRT-PCR). The localization of miR-101-5p in term placental tissue and decidual tissue was determined by the fluorescence in situ hybridization (FISH)-immunofluorescence (IF) double labeling assay. The effect of miR-101-5p on the migration, invasion, proliferation, and apoptosis of the HTR8/SVneo trophoblast cells was investigated. Online databases combined with transcriptomics were used to identify potential target genes and related pathways of miR-101-5p. Finally, the interaction between miR-101-5p and the target gene was verified by qRT-PCT, WB, dual-luciferase reporter assay, and rescue experiments.

RESULTS

The study found that miR-101-5p was upregulated in PE placental tissue compared to normal controls and was mainly located in various trophoblast cell subtypes in placental and decidual tissues. Overexpression of miR-101-5p impaired the migration and invasion of HTR8/SVneo cells. DUSP6 was identified as a potential downstream target of miR-101-5p. The expression of miR-101-5p was negatively correlated with DUSP6 expression in HTR8/SVneo cells, and miR-101-5p directly bound to the 3' UTR region of DUSP6. DUSP6 upregulation rescued the migratory and invasive abilities of HTR8/SVneo cells in the presence of miR-101-5p overexpression. Additionally, miR-101-5p downregulated DUSP6, resulting in enhanced ERK1/2 phosphorylation.

CONCLUSION

This study revealed that miR-101-5p inhibits the migration and invasion of HTR8/SVneo cells by regulating the DUSP6-ERK1/2 axis, providing a new molecular mechanism for the pathogenesis of PE.

Molecular subclasses of preeclampsia characterized by a longitudinal maternal proteomics study: distinct biomarkers, disease pathways and options for prevention

OBJECTIVES

The heterogeneous nature of preeclampsia is a major obstacle to early screening and prevention, and a molecular taxonomy of disease is needed. We have previously identified four subclasses of preeclampsia based on first-trimester plasma proteomic profiles. Herein, we expanded this approach by using a more comprehensive panel of proteins profiled in longitudinal samples.

METHODS

Proteomic data collected longitudinally from plasma samples of women who developed preeclampsia (n=109) and of controls (n=90) were available from our previous report on 1,125 proteins. Consensus clustering was performed to identify subgroups of patients with preeclampsia based on data from five gestational-age intervals by using select interval-specific features. Demographic, clinical, and proteomic differences among clusters were determined. Differentially abundant proteins were used to identify cluster-specific perturbed KEGG pathways.

RESULTS

Four molecular clusters with different clinical phenotypes were discovered by longitudinal proteomic profiling. Cluster 1 involves metabolic and prothrombotic changes with high rates of early-onset preeclampsia and small-for-gestational-age neonates; Cluster 2 includes maternal anti-fetal rejection mechanisms and recurrent preeclampsia cases; Cluster 3 is associated with extracellular matrix regulation and comprises cases of mostly mild, late-onset preeclampsia; and Cluster 4 is characterized by angiogenic imbalance and a high prevalence of early-onset disease.

CONCLUSIONS

This study is an independent validation and further refining of molecular subclasses of preeclampsia identified by a different proteomic platform and study population. The results lay the groundwork for novel diagnostic and personalized tools of prevention.

Diagnostic signature and immune characteristic of aging-related genes from placentas in Preeclampsia

INTRODUCTION

Preeclampsia (PE) is a serious pregnancy syndrome. Advanced maternal age (≥ 35 years old) is one of the major risk factors of PE and placental aging is considered to be related to this disease. However, the mechanisms underlying these phenomena remain obscured.

METHODS

Gene expression profiles of PE and non-PE placental samples were curated from the GSE75010 dataset. A diagnostic model was constructed and immune characteristics of PE subtypes were estimated.

RESULTS

A total of 58 aging-related genes, which may be associated with PE, were identified. Among them, LEP and FLT1 may be key aging-related genes. Based on 5 top genes (PIK3CB, FLT1, LEP, PIK3R1, CSNK1E), a diagnostic nomogram for PE was built (AUC = 0.872 in the GSE75010 dataset). Three molecular subtypes were clustered, which had different immune and angiogenesis characteristics.

CONCLUSION

The present study suggests the potential implications of aging-related genes in diagnosing PE. Diverse immune characteristics may be involved in the placental aging of PE.

Proteoglycans: Systems-Level Insight into Their Expression in Healthy and Diseased Placentas

Proteoglycan macromolecules play key roles in several physiological processes (e.g., adhesion, proliferation, migration, invasion, angiogenesis, and apoptosis), all of which are important for placentation and healthy pregnancy. However, their precise roles in human reproduction have not been clarified. To fill this gap, herein, we provide an overview of the proteoglycans' expression and role in the placenta, in trophoblast development, and in pregnancy complications (pre-eclampsia, fetal growth restriction), highlighting one of the most important members of this family, syndecan-1 (SDC1). Microarray data analysis showed that of 34 placentally expressed proteoglycans, SDC1 production is markedly the highest in the placenta and that SDC1 is the most upregulated gene during trophoblast differentiation into the syncytiotrophoblast. Furthermore, placental transcriptomic data identified dysregulated proteoglycan genes in pre-eclampsia and in fetal growth restriction, including SDC1, which is supported by the lower concentration of syndecan-1 in maternal blood in these syndromes. Overall, our clinical and in vitro studies, data analyses, and literature search pointed out that proteoglycans, as important components of the placenta, may regulate various stages of placental development and participate in the maintenance of a healthy pregnancy. Moreover, syndecan-1 may serve as a useful marker of syncytialization and a prognostic marker of adverse pregnancy outcomes. Further studies are warranted to explore the role of proteoglycans in healthy and complicated pregnancies, which may help in diagnostic or therapeutic developments.

Alpha 1 Antitrypsin Regulates Trophoblast Syncytialization and Inflammatory Factor Expression

The serine protease inhibitor alpha1-antitrypsin (A1AT) may possess protective functions of impaired organs in a manner independent of its protease inhibitor activity. A1AT expression has been shown to fluctuate in patients with pregnancy-induced hypertension, which suggests that A1AT may play a role in the syncytialization of villous trophoblasts. A1AT expression was knocked down in primary trophoblasts. RNA was extracted from these cells and subjected to RNA-sequencing analysis to determine the levels of expression of markers of syncytialization and inflammation. In addition, A1AT protein was localized in trophoblastic cells in placental tissues. Knockdown of A1AT upregulated the expression of FOSL1 and markers of syncytialization, as well as cell fusion, whereas overexpression of A1AT had the opposite effects. FOSL1 overexpression stimulated syncytialization, similar to the effects of A1AT knock down. Inhibitors of p38MAPK and JNK reduce the expression of inflammatory factors, whereas a p38MAPK inhibitor suppressed FOSL1 expression. Collectively, these findings indicated A1AT may negatively regulate inflammatory responses by controlling the activation of p38MAPK and JNK, and that p38MAPK mediates trophoblast syncytialization by altering FOSL1 expression. Therefore, a dysfunction in A1AT could be responsible for abnormal placental formation and pregnancy-associated disorders.

Human Placental NADPH Oxidase Mediates sFlt-1 and PlGF Secretion in Early Pregnancy: Exploration of the TGF-β1/p38 MAPK Pathways

Preeclampsia, a hypertensive disorder occurring during pregnancy, is characterized by excessive oxidative stress and trophoblast dysfunction with dysregulation of soluble Fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF) production. Nicotinamide Adenine Dinucleotide Phosphate (NADPH) oxidase (Nox) is the major source of placental superoxide in early pregnancy and its activation with the subsequent formation of superoxide has been demonstrated for various agents including Transforming Growth Factor beta-1 (TGF-β1), a well-known p38 MAPK pathway activator. However, the bridge between Nox and sFlt-1 remains unknown. The purpose of this study was to explore the possible signaling pathway of TGF-β1/Nox/p38 induced sFlt-1 production in human chorionic villi (CV). Methods: Human chorionic villi from first trimester placenta (7–9 Gestational Weeks (GW)) were treated with TGF-β1 or preincubated with p38 inhibitor, SB203580. For NADPH oxidase inhibition, CV were treated with diphenyleneiodonium (DPI). The protein levels of phospho-p38, p38, phospho-Mothers Against Decapentaplegic homolog 2 (SMAD2), and SMAD2 were detected by Western blot. The secretion of sFlt-1 and PlGF by chorionic villi were measured with Electrochemiluminescence Immunologic Assays, and NADPH oxidase activity was monitored by lucigenin method. Results: We demonstrate for the first time that NADPH oxidase is involved in sFlt-1 and PlGF secretion in first trimester chorionic villi. Indeed, the inhibition of Nox by DPI decreases sFlt-1, and increases PlGF secretions. We also demonstrate the involvement of p38 MAPK in sFlt-1 secretion and Nox activation as blocking the p38 MAPK phosphorylation decreases both sFlt-1 secretion and superoxide production. Nevertheless, TGF-β1-mediated p38 activation do not seem to be involved in regulation of the first trimester placental angiogenic balance and no crosstalk was found between SMAD2 and p38 MAPK pathways. Conclusions: Thus, the placental NADPH oxidase play a major role in mediating the signal transduction cascade of sFlt-1 production. Furthermore, we highlight for the first time the involvement of p38 activation in first trimester placental Nox activity.

Human Umbilical Cord Mesenchymal Stem Cells-Derived Exosomal MicroRNA-18b-3p Inhibits the Occurrence of Preeclampsia by Targeting LEP

Exosomes derived from human umbilical cord mesenchymal stem cells (hucMSCs) expressing microRNAs have been highlighted in human diseases. However, the detailed molecular mechanism of hucMSCs-derived exosomal miR-18b-3p on preeclampsia (PE) remains further investigation. We aimed to investigate the effect of exosomes and miR-18b-3p/leptin (LEP) on occurrence of PE. The morphology of the hucMSC and hucMSC-exosomes (Exos) was identified. The exosomes were infected with different lentivirus expressing miR-18b-3p to explore the role of miR-18b-3p in PE. The PE rat model was established by intraperitoneal injection of N-nitro-L-arginine methyl ester. The expression of LEP and miR-18b-3p was tested in PE rat placenta tissues. Also, the effect of exosomes on LEP and miR-18b-3p expression was detected. The systolic blood pressure (SBP), proteinuria, inflammatory factors, the weight of fetal rat and placenta and cell apoptosis in PE rats were detected. Finally, the relationship between miR-18b-3p and LEP was verified using dual-luciferase reporter gene assay and RNA pull-down assay. Exosomes, restoring miR-18b-3p or inhibiting LEP reduced SBP and proteinuria of PE rats as well as increased the weight of fetal rat and placenta, decreased serum levels of inflammatory factors as well as suppressed apoptotic cells of PE rats, exerting a suppressive effect on PE progression. miR-18b-3p was decreased and LEP was increased in placenta tissues of PE rats. LEP was the direct target gene of miR-18b-3p. Upregulation of miR-18b-3p or treatment of the exosomes suppressed LEP expression and reduced PE occurrence, while downregulation of miR-18b-3p had contrary effects. Downregulated LEP reversed the effect of miR-18b-3p reduction on PE rats. HucMSCs-derived exosomal miR-18b-3p targets LEP to participate in the occurrence and development of PE. This study may provide a novel theoretical basis for the mechanism and investigation of PE.

Proteomic identification of Placental Protein 1 (PP1), PP8, and PP22 and characterization of their placental expression in healthy pregnancies and in preeclampsia

INTRODUCTION

Placental Protein 1 (PP1), PP8, and PP22 were isolated from the placenta. Herein, we aimed to identify PP1, PP8, and PP22 proteins and their placental and trophoblastic expression patterns to reveal potential involvement in pregnancy complications.

METHODS

We analyzed PP1, PP8, and PP22 proteins with LC-MS. We compared the placental behaviors of PP1, PP8, and PP22 to the predominantly placenta-expressed PP5/TFPI-2. Placenta-specificity scores were generated from microarray data. Trophoblasts were isolated from healthy placentas and differentiated; total RNA was isolated and subjected to microarray analysis. We assigned the placentas to the following groups: preterm controls, early-onset preeclampsia, early-onset preeclampsia with HELLP syndrome, term controls, and late-onset preeclampsia. After histopathologic examination, placentas were used for tissue microarray construction, immunostaining with anti-PP1, anti-PP5, anti-PP8, or anti-PP22 antibodies, and immunoscoring.

RESULTS

PP1, PP8, and PP22 were identified as 'nicotinate-nucleotide pyrophosphorylase', 'serpin B6', and 'protein disulfide-isomerase', respectively. Genes encoding PP1, PP8, and PP22 are not predominantly placenta-expressed, in contrast with PP5. PP1, PP8, and PP22 mRNA expression levels did not increase during trophoblast differentiation, in contrast with PP5. PP1, PP8, and PP22 immunostaining were detected primarily in trophoblasts, while PP5 expression was restricted to the syncytiotrophoblast. The PP1 immunoscore was higher in late-onset preeclampsia, while the PP5 immunoscore was higher in early-onset preeclampsia.

DISCUSSION

PP1, PP8, and PP22 are expressed primarily in trophoblasts but do not have trophoblast-specific regulation or functions. The distinct dysregulation of PP1 and PP5 expression in either late-onset or early-onset preeclampsia reflects different pathophysiological pathways in these preeclampsia subsets.

Perfluorobutane sulfonate exposure disrupted human placental cytotrophoblast cell proliferation and invasion involving in dysregulating preeclampsia related genes

We reported that maternal PFBS, an emerging pollutant, exposure is positively associated with preeclampsia which can result from aberrant trophoblasts invasion and subsequent placental ischemia. In this study, we investigated the effects of PFBS on trophoblasts proliferation/invasion and signaling pathways. We exposed a human trophoblast line, HTR8/SVneo, to PFBS. Cell viability, proliferation, and cell cycle were evaluated by the MTS assay, Ki-67 staining, and flow cytometry, respectively. We assessed cell migration and invasion with live-cell imaging-based migration assay and matrigel invasion assay, respectively. Signaling pathways were examined by Western blot, RNA-seq, and qPCR. PFBS exposure interrupted cell proliferation and invasion in a dose-dependent manner. PFBS (100 μM) did not cause cell death but instead significant cell proliferation without cell cycle disruption. PFBS (10 and 100 μM) decreased cell migration and invasion, while PFBS (0.1 μM) significantly increased cell invasion but not migration. Further, RNA-seq analysis identified dysregulated HIF-1α target genes that are relevant to cell proliferation/invasion and preeclampsia, while Western Blot data showed the activation of HIF-1α, but not Notch, ERK1/2, (PI3K)AKT, and P38 pathways. PBFS exposure altered trophoblast cell proliferation/invasion which might be mediated by preeclampsia-related genes, suggesting a possible association between prenatal PFBS exposure and adverse placentation.

Insulin Therapy in Pregnancy Hypertensive Diseases and its Effect on the Offspring and Mother Later in Life

Pregnancy hypertensive disorders such as Preeclampsia (PE) are strongly correlated with insulin resistance, a condition in which the metabolic handling of D-glucose is deficient. In addition, the impact of preeclampsia is enhanced by other insulin-resistant disorders, including polycystic ovary syndrome and obesity. For this reason, there is a clear association between maternal insulin resistance, polycystic ovary syndrome, obesity and the development of PE. However, whether PE is a consequence or the cause of these disorders is still unclear. Insulin therapy is usually recommended to pregnant women with diabetes mellitus when dietary and lifestyle measures have failed. The advantage of insulin therapy for Gestational Diabetes Mellitus (GDM) patients with hypertension is still controversial; surprisingly, there are no studies in which insulin therapy has been used in patients with hypertension in pregnancy without or with an established GDM. This review is focused on the use of insulin therapy in hypertensive disorders in the pregnancy and its effect on offspring and mother later in life. PubMed and relevant medical databases have been screened for literature covering research in the field especially in the last 5-10 years.

Innate and Adaptive Immune Responses in HELLP Syndrome

Innate and adaptive immune involvement in hemolysis, elevated liver enzymes and low platelet (HELLP) syndrome is an understudied field, although it is of high clinical importance. This syndrome implies a risk of serious morbidity and mortality to both the mother and the fetus during pregnancy. It was proposed that HELLP syndrome occurs in a circulatory inflammatory milieu, that might in turn participate in a complex interplay between the secreted inflammatory immunomodulators and immune cell surface receptors. Meanwhile, reported immune cell attenuation during HELLP may consequently lead to a prolonged immunoactivation and tissue damage. In this regard, learning more about the immune components of this syndrome should widen the understanding of the HELLP pathophysiology and eventually enable development of novel immune-based therapeutics. This review aims to summarize and discuss the recent and previous findings of the innate and adaptive immune responses during HELLP in order to update the current knowledge of the immune involvement in HELLP pathogenesis.

Placenta-Specific Genes, Their Regulation During Villous Trophoblast Differentiation and Dysregulation in Preterm Preeclampsia

The human placenta maintains pregnancy and supports the developing fetus by providing nutrition, gas-waste exchange, hormonal regulation, and an immunological barrier from the maternal immune system. The villous syncytiotrophoblast carries most of these functions and provides the interface between the maternal and fetal circulatory systems. The syncytiotrophoblast is generated by the biochemical and morphological differentiation of underlying cytotrophoblast progenitor cells. The dysfunction of the villous trophoblast development is implicated in placenta-mediated pregnancy complications. Herein, we describe gene modules and clusters involved in the dynamic differentiation of villous cytotrophoblasts into the syncytiotrophoblast. During this process, the immune defense functions are first established, followed by structural and metabolic changes, and then by peptide hormone synthesis. We describe key transcription regulatory molecules that regulate gene modules involved in placental functions. Based on transcriptomic evidence, we infer how villous trophoblast differentiation and functions are dysregulated in preterm preeclampsia, a life-threatening placenta-mediated obstetrical syndrome for the mother and fetus. In the conclusion, we uncover the blueprint for villous trophoblast development and its impairment in preterm preeclampsia, which may aid in the future development of non-invasive biomarkers for placental functions and early identification of women at risk for preterm preeclampsia as well as other placenta-mediated pregnancy complications.

Dysregulation of Placental Functions and Immune Pathways in Complete Hydatidiform Moles

Gene expression studies of molar pregnancy have been limited to a small number of candidate loci. We analyzed high-dimensional RNA and protein data to characterize molecular features of complete hydatidiform moles (CHMs) and corresponding pathologic pathways. CHMs and first trimester placentas were collected, histopathologically examined, then flash-frozen or paraffin-embedded. Frozen CHMs and control placentas were subjected to RNA-Seq, with resulting data and published placental RNA-Seq data subjected to bioinformatics analyses. Paraffin-embedded tissues from CHMs and control placentas were used for tissue microarray (TMA) construction, immunohistochemistry, and immunoscoring for galectin-14. Of the 14,022 protein-coding genes expressed in all samples, 3,729 were differentially expressed (DE) in CHMs, of which 72% were up-regulated. DE genes were enriched in placenta-specific genes (OR = 1.88, p = 0.0001), of which 79% were down-regulated, imprinted genes (OR = 2.38, p = 1.54 × 10-6), and immune genes (OR = 1.82, p = 7.34 × 10-18), of which 73% were up-regulated. DNA methylation-related enzymes and histone demethylases were dysregulated. "Cytokine-cytokine receptor interaction" was the most impacted of 38 dysregulated pathways, among which 17 were immune-related pathways. TMA-based immunoscoring validated the lower expression of galectin-14 in CHM. In conclusion, placental functions were down-regulated, imprinted gene expression was altered, and immune pathways were activated, indicating complex dysregulation of placental developmental and immune processes in CHMs.

The Effect of BML-111 in Preeclampsia Rat Model Induced by the Low Dose of Cadmium Chloride

Aim  This article determines the optimal time and dose of cadmium chloride (CdCl ₂ ) injected to pregnant rat to establish experimental preeclampsia (PE) model. In addition, the therapeutic potential of BML-111, a lipoxin A4 analogue, in the CdCl ₂ -induced PE model was also evaluated. Methods  Peritoneal injection of two dose of CdCl ₂ for successive 6 days was tested in the pregnant rats starting from various gestational days (GDs). During this process, the systolic blood pressure and the body weight of pregnant rats and neonatal rats were monitored. The pathological changes of the placenta and kidney were evaluated by hematoxylin and eosin staining. The phosphorylation of extracellular signal-regulated kinase 1/2 and signal transducer and activator of transcription 3 in the placentas was detected by Western blot, and the messenger ribonucleic acid expression of interleukin (IL)-6, tumor necrosis factor-α, and IL-10 in the placentas were detected by real-time polymerase chain reaction. BML-111 at the dose of 1 mg/kg/day was peritoneally injected into the rat after establishing the PE model to test its therapeutic potential. Results  In the present study, we successfully established the PE model in pregnant rats by intraperitoneally injection of CdCl ₂ at the dose of 0.125 mg/kg/day from GD 9 to 14. We recapitulated multiple features of clinical PE in CdCl ₂ -induced rat, including high blood pressure, renal dysfunction, and inflammatory response in placenta. Furthermore, treatment with BML-111 significantly relieved multiple features in our PE rat model. Conclusions  BML-111 has a potential therapeutic effect in pregnant rats with CdCl ₂ -induced PE, which appears to be mediated through inhibition of inflammatory processes in the placenta.

Proteomic identification of membrane-associated placental protein 4 (MP4) as perlecan and characterization of its placental expression in normal and pathologic pregnancies

Background

More than 50 human placental proteins were isolated and physico-chemically characterized in the 70–80s by Hans Bohn and co-workers. Many of these proteins turned to have important role in placental functions and diagnostic significance in pregnancy complications. Among these proteins was membrane-associated placental protein 4 (MP4), for which identity or function has not been identified yet. Our aim was to analyze the sequence and placental expression of this protein in normal and complicated pregnancies including miscarriage, preeclampsia and HELLP syndrome.

Methods

Lyophilized MP4 protein and frozen healthy placental tissue were analyzed using HPLC-MS/MS. Placental tissue samples were obtained from women with elective termination of pregnancy (first trimester controls, n = 31), early pregnancy loss (EPL) (n = 13), early preeclampsia without HELLP syndrome (n = 7) and with HELLP syndrome (n = 8), late preeclampsia (n = 8), third trimester early controls (n = 5) and third trimester late controls (n = 9). Tissue microarrays were constructed from paraffin-embedded placentas (n = 81). Slides were immunostained with monoclonal perlecan antibody and evaluated using light microscopy and virtual microscopy. Perlecan was also analyzed for its expression in placentas from normal pregnancies using microarray data.

Results

Mass spectrometry-based proteomics of MP4 resulted in the identification of basement membrane-specific heparan sulfate proteoglycan core protein also known as perlecan. Immunohistochemistry showed cytoplasmic perlecan localization in syncytiotrophoblast and cytotrophoblasts of the villi. Perlecan immunoscore decreased with gestational age in the placenta. Perlecan immunoscores were higher in EPL compared to controls. Perlecan immunoscores were higher in early preeclampsia without and with HELLP syndrome and lower in late preeclampsia than in respective controls. Among patients with preeclampsia, placental perlecan expression positively correlated with maternal vascular malperfusion and negatively correlated with placental weight.

Conclusion

Our findings suggest that an increased placental perlecan expression may be associated with hypoxic ischaemic injury of the placenta in miscarriages and in early preeclampsia with or without HELLP syndrome.

Placental Galectins Are Key Players in Regulating the Maternal Adaptive Immune Response

Galectins are potent immunomodulators that regulate maternal immune responses in pregnancy and prevent the rejection of the semi-allogeneic fetus that also occurs in miscarriages. We previously identified a gene cluster on Chromosome 19 that expresses a subfamily of galectins, including galectin-13 (Gal-13) and galectin-14 (Gal-14), which emerged in anthropoid primates. These galectins are expressed only by the placenta and induce the apoptosis of activated T lymphocytes, possibly contributing to a shifted maternal immune balance in pregnancy. The placental expression of Gal-13 and Gal-14 is decreased in preeclampsia, a life-threatening obstetrical syndrome partly attributed to maternal anti-fetal rejection. This study is aimed at revealing the effects of Gal-13 and Gal-14 on T cell functions and comparing the expression of these galectins in placentas from healthy pregnancies and miscarriages. First-trimester placentas were collected from miscarriages and elective termination of pregnancies, tissue microarrays were constructed, and then the expression of Gal-13 and Gal-14 was analyzed by immunohistochemistry and immunoscoring. Recombinant Gal-13 and Gal-14 were expressed and purified, and their effects were investigated on primary peripheral blood T cells. The binding of Gal-13 and Gal-14 to T cells and the effects of these galectins on apoptosis, activation marker (CD25, CD71, CD95, HLA-DR) expression and cytokine (IL-1β, IL-6, IL-8, IL-10, IFNγ) production of T cells were examined by flow cytometry. Gal-13 and Gal-14 are primarily expressed by the syncytiotrophoblast at the maternal-fetal interface in the first trimester, and their placental expression is decreased in miscarriages compared to first-trimester controls. Recombinant Gal-13 and Gal-14 bind to T cells in a population- and activation-dependent manner. Gal-13 and Gal-14 induce apoptosis of Th and Tc cell populations, regardless of their activation status. Out of the investigated activation markers, Gal-14 decreases the cell surface expression of CD71, Gal-13 increases the expression of CD25, and both galectins increase the expression of CD95 on T cells. Non-activated T cells produce larger amounts of IL-8 in the presence of Gal-13 or Gal-14. In conclusion, these results show that Gal-13 and Gal-14 already provide an immunoprivileged environment at the maternal-fetal interface during early pregnancy, and their reduced expression is related to miscarriages.

miR-141-5p regulate ATF2 via effecting MAPK1/ERK2 signaling to promote preeclampsia

OBJECTIVE

Preeclampsia is a pregnancy-specific syndrome characterized by hypertension and proteinuria. Impaired trophoblast invasion partly modulated by abnormal MAPK1/ERK2 signaling played important roles in the pathological process of preeclampsia. The objective of this study is to investigate miR-141-5p regulate ATF2 via effecting MAPK1/ERK2 signaling to promote preeclampsia.

STUDY DESIGN

The maternal placentae and clinical data of 30 patients with preeclampsia and 30 healthy pregnant women were collected in the Second Hospital of Shanxi Medical University from July 2015 to April 2016. Transcriptional levels of miR-141-5p in placentae were monitored using quantitative real-time reverse transcription-polymerase chain reaction. The target gene of miR-141-5p was analyzed with "TargetScanHuman Release 7.2″. To evaluate the pathways of this response, MAPK1 and ERK1/2 in placentae were detected using immunohistochemistry and Western Blot. Transfection experiment was used to verify the function of miR-141-5p regulating ATF2 to effect MAPK1/ERK2 signaling in JEG-3 cells.

RESULTS

miR-141-5p was significantly down-regulated in placentae of patients with preeclampsia, in comparison to the healthy pregnant women groups. There was no difference in MAPK1 expression between placentae of patients with preeclampsia and healthy pregnant women groups. While p-MAPK1 expression was lower in preeclampsia placentae, in comparison to the healthy pregnant women groups. Moreover, inhibition and activation experiments also validate the function of miR-141-5p in effecting p-MAPK1 level in JEG-3 cells. Bioinformatic analysis identified that ATF2 was a target gene of miR-141-5p, which was one DNA-binding protein to effect phosphatase DUSP1 transcription. DUSP1 effect MAPK1/ERK2 signaling in preeclampsia.

CONCLUSION

miR-141-5p up-regulated transcription factor ATF2 to promote phosphatase DUSP1 expression. DUSP1 expression reduces p-MAPK1 and ERK1/2 expression to promote preeclampsia.

Low-dose aspirin reduces hypoxia-induced sFlt1 release via the JNK/AP-1 pathway in human trophoblast and endothelial cells

Pre-eclampsia (PE) is a serious hypertensive disorder of pregnancy that remains a leading cause of perinatal and maternal morbidity and mortality worldwide. Placental ischemia/hypoxia and the secretion of soluble fms-like tyrosine kinase 1 (sFlt1) into maternal circulation are involved in the pathogenesis of PE. Although low-dose aspirin (LDA) has beneficial effects on the prevention of PE, the exact mechanisms of action of LDA, particularly on placental dysfunction, and sFlt1 release, have not been well investigated. This study aimed to determine whether LDA exists the protective effects on placental trophoblast and endothelial functions and prevents PE-associated sFlt1 release. First, we observed that LDA mitigated hypoxia-induced trophoblast apoptosis, showed positive effects on trophoblast cells migration and invasion activity, and increased the tube-forming activity of human umbilical vein endothelial cells (HUVECs). In addition, LDA decreased hypoxia-induced sFlt1 production, and the c-Jun NH₂ -terminal kinase/activator protein-1 (JNK/AP-1) pathway was shown to mediate the induction of sFlt1. Moreover, the transcription factor AP-1 was confirmed to regulate the Flt1 gene expression by directly binding to the Flt1 promoter in luciferase assays. The result of chromatin immunoprecipitation assays further demonstrated that LDA could directly decrease the expression of the transcription factor AP-1, and thus decrease sFlt1 production. Finally, the effects of LDA on sFlt1 production were proved in human placental explants. Taken together, our data show the protective effects of LDA against trophoblast and endothelial cell dysfunction and reveal that the LDA-mediated inhibition of sFlt1 via the JNK/AP-1 pathway may be a potential cellular/molecular mechanism for the prevention of PE.

Increased placental expression of Placental Protein 5 (PP5) / Tissue Factor Pathway Inhibitor-2 (TFPI-2) in women with preeclampsia and HELLP syndrome: Relevance to impaired trophoblast invasion?

INTRODUCTION

Placental Protein 5 (PP5)/Tissue Factor Pathway Inhibitor-2 (TFPI-2) is an extracellular matrix-associated protein mainly expressed by the syncytiotrophoblast that may regulate trophoblast invasion. Our aim was to study placental PP5/TFPI-2 expression and its relation to placental pathology in various forms of preeclampsia and HELLP syndrome.

METHODS

Placental and maternal blood specimens were collected at the time of delivery from the same women in the following groups: 1) early controls; 2) early preeclampsia; 3) early preeclampsia with HELLP syndrome; 4) late controls; and 5) late preeclampsia. After histopathological examination, placental specimens were immunostained with polyclonal anti-PP5/TFPI-2 antibody on Western blot and tissue microarray immunohistochemistry. Placental PP5/TFPI-2 immunoscores were assessed manually and with a semi-automated method. Maternal sera were immunoassayed for PP5/TFPI-2.

RESULTS

PP5/TFPI-2 was localized to the cytoplasm of syncytiotrophoblast. Manual and semi-automated PP5/TFPI-2 immunoscores were higher in early preeclampsia with or without HELLP syndrome but not in late preeclampsia than in respective controls. In patients with preeclampsia, the correlation of placental PP5/TFPI-2 expression with maternal vascular malperfusion score of the placenta was positive while it was negative with birthweight and placental weight. Maternal serum PP5/TFPI-2 concentration was higher in early preeclampsia and it tended to be higher in early preeclampsia with HELLP syndrome than in early controls.

DISCUSSION

Our findings suggest that an increased placental PP5/TFPI-2 expression may be associated with abnormal placentation in early preeclampsia, with or without HELLP syndrome.

The frequency and type of placental histologic lesions in term pregnancies with normal outcome

Objective To determine the frequency and type of histopathologic lesions in placentas delivered by women with a normal pregnancy outcome. Methods This retrospective cohort study included placental samples from 944 women with a singleton gestation who delivered at term without obstetrical complications. Placental lesions were classified into the following four categories as defined by the Society for Pediatric Pathology and by our unit: (1) acute placental inflammation, (2) chronic placental inflammation, (3) maternal vascular malperfusion and (4) fetal vascular malperfusion. Results (1) Seventy-eight percent of the placentas had lesions consistent with inflammatory or vascular lesions; (2) acute inflammatory lesions were the most prevalent, observed in 42.3% of the placentas, but only 1.0% of the lesions were severe; (3) acute inflammatory lesions were more common in the placentas of women with labor than in those without labor; (4) chronic inflammatory lesions of the placenta were present in 29.9%; and (5) maternal and fetal vascular lesions of malperfusion were detected in 35.7% and 19.7%, respectively. Two or more lesions with maternal or fetal vascular features consistent with malperfusion (high-burden lesions) were present in 7.4% and 0.7%, respectively. Conclusion Most placentas had lesions consistent with inflammatory or vascular lesions, but severe and/or high-burden lesions were infrequent. Mild placental lesions may be interpreted either as acute changes associated with parturition or as representative of a subclinical pathological process (intra-amniotic infection or sterile intra-amniotic inflammation) that did not affect the clinical course of pregnancy.

Metformin, the aspirin of the 21st century: its role in gestational diabetes mellitus, prevention of preeclampsia and cancer, and the promotion of longevity

Metformin is everywhere. Originally introduced in clinical practice as an antidiabetic agent, its role as a therapeutic agent is expanding to include treatment of prediabetes mellitus, gestational diabetes mellitus, and polycystic ovarian disease; more recently, experimental studies and observations in randomized clinical trials suggest that metformin could have a place in the treatment or prevention of preeclampsia. This article provides a brief overview of the history of metformin in the treatment of diabetes mellitus and reviews the results of metaanalyses of metformin in gestational diabetes mellitus as well as the treatment of obese, non-diabetic, pregnant women to prevent macrosomia. We highlight the results of a randomized clinical trial in which metformin administration in early pregnancy did not reduce the frequency of large-for-gestational-age infants (the primary endpoint) but did decrease the frequency of preeclampsia (a secondary endpoint). The mechanisms by which metformin may prevent preeclampsia include a reduction in the production of antiangiogenic factors (soluble vascular endothelial growth factor receptor-1 and soluble endoglin) and the improvement of endothelial dysfunction, probably through an effect on the mitochondria. Another potential mechanism whereby metformin may play a role in the prevention of preeclampsia is its ability to modify cellular homeostasis and energy disposition, mediated by rapamycin, a mechanistic target. Metformin has a molecular weight of 129 Daltons and therefore readily crosses the placenta. There is considerable evidence to suggest that this agent is safe during pregnancy. New literature on the role of metformin as a chemotherapeutic adjuvant in the prevention of cancer and in prolonging life and protecting against aging is reviewed briefly. Herein, we discuss the mechanisms of action and potential benefits of metformin.

Akt/mTOR Role in Human Foetoplacental Vascular Insulin Resistance in Diseases of Pregnancy

Insulin resistance is characteristic of pregnancies where the mother shows metabolic alterations, such as preeclampsia (PE) and gestational diabetes mellitus (GDM), or abnormal maternal conditions such as pregestational maternal obesity (PGMO). Insulin signalling includes activation of insulin receptor substrates 1 and 2 (IRS1/2) as well as Src homology 2 domain-containing transforming protein 1, leading to activation of 44 and 42 kDa mitogen-activated protein kinases and protein kinase B/Akt (Akt) signalling cascades in the human foetoplacental vasculature. PE, GDM, and PGMO are abnormal conditions coursing with reduced insulin signalling, but the possibility of the involvement of similar cell signalling mechanisms is not addressed. This review aimed to determine whether reduced insulin signalling in PE, GDM, and PGMO shares a common mechanism in the human foetoplacental vasculature. Insulin resistance in these pathological conditions results from reduced Akt activation mainly due to inhibition of IRS1/2, likely due to the increased activity of the mammalian target of rapamycin (mTOR) resulting from lower activity of adenosine monophosphate kinase. Thus, a defective signalling via Akt/mTOR in response to insulin is a central and common mechanism of insulin resistance in these diseases of pregnancy. In this review, we summarise the cell signalling mechanisms behind the insulin resistance state in PE, GDM, and PGMO focused in the Akt/mTOR signalling pathway in the human foetoplacental endothelium.

Polymorphisms in Inflammatory Mediator Genes and Risk of Preeclampsia in Taiyuan, China

Excessive maternal inflammatory response is involved in the pathogenesis of preeclampsia. Few epidemiologic studies have investigated the associations between genetic variations in the inflammatory mediator genes and preeclampsia risk, and these studies have reached inconsistent results. We examined 31 single-nucleotide polymorphisms in IL-1A, IL-1B, IL-1R1, IL-2RA, IL-5RA, IL-6, IL-6R, TNFSF11, TNFRSF11A, IL-28RA, IRAK4, and KIT genes and the risk of preeclampsia and its clinical subtypes in a nested case-control study including 203 preeclampsia cases and 233 controls. We found that IL-1R1, IL-5RA, IL-6R, and TNFSF11 were associated with the risk of preeclampsia. Although the significant associations observed for preeclampsia overall were mainly seen for late-onset preeclampsia and severe preeclampsia, IL-6R (rs2229238) and TNFSF11 (rs9525643) polymorphisms were associated with the risk of early-onset preeclampsia. TNFSF11 (rs2200287 and rs2148072) polymorphisms were associated with risk of mild preeclampsia. Our study provided the first evidence that genetic variations in inflammatory mediator genes IL-1R1, IL-6R, TNFSF11, and IL-5RA were associated with preeclampsia risk, and the risk varied by preeclampsia subtypes.

Interferon-Gamma and Fas Are Involved in Porphyromonas gingivalis-Induced Apoptosis of Human Extravillous Trophoblast-Derived HTR8/SVneo Cells via Extracellular Signal-Regulated Kinase 1/2 Pathway

BACKGROUND

A number of studies recently revealed a link between periodontal disease and preterm birth (PTB). PTB can be induced by dental infection with Porphyromonas gingivalis (Pg), a periodontopathic bacterium. This study aims to investigate responses of human extravillous trophoblast-derived HTR8/SVneo cells to Pg infection.

METHODS

Cell apoptosis, cell viability, protein expression, and cytokine production in HTR8 cells were measured via: 1) flow cytometry, 2) CCK-8 assay, 3) western blot, and 4) enzyme-linked immunosorbent assay methods, respectively.

RESULTS

Pg decreased cell viability and increased cell apoptosis, active caspase-3 and Fas expression, and interferon-gamma (IFN-γ) secretion in HTR8 cells. Extracellular signal-regulated kinase (ERK) 1/2 inhibitor U0126 and FasL neutralizing antibody NOK1 that blocks FasL/Fas interaction both significantly suppressed Pg-induced apoptosis. U0126 also inhibited IFN-γ secretion and Fas expression close to control levels. Moreover, treatment with recombinant IFN-γ also significantly decreased number of viable HTR8 cells and increased Fas expression, suggesting IFN-γ may play an important role in Pg-induced apoptosis of HTR8 cells, at least partially through regulation of Fas expression.

CONCLUSIONS

To the best of the authors' knowledge, this is the first study to demonstrate Pg induces IFN-γ secretion, Fas expression, and apoptosis in human extravillous trophoblast-derived HTR8/SVneo cells in an ERK1/2-dependent manner, and IFN-γ (explored by recombinant IFN-γ) and Fas are involved in Pg-induced apoptosis. The finding that Pg infection abnormally regulates inflammation and apoptosis of human trophoblasts may give new insights into the possible link of PTB with maternal periodontal disease and periodontal pathogens.

Alpha-1 Antitrypsin Prevents the Development of Preeclampsia Through Suppression of Oxidative Stress

Preeclampsia (PE) and its complications have become the leading cause of maternal and fetal morbidity and mortality in the world. And the development of PE is still barely predictable and thus challenging to prevent and manage clinically. Oxidative stress contributes to the development of the disease. Our previous study demonstrated that exogenous Alpha-1 antitrypsin (AAT) played a cytoprotective role in vascular endothelial cell by suppressing oxidative stress. In this study, we aim to investigate whether AAT contributes to the development of PE, and to identify the mechanism behind these effects. We found that AAT levels were significantly decreased in placenta tissues from women with PE compared that of healthy women. Notably, we demonstrate that AAT injection is able to relieve the high blood pressure and reduce urine protein levels in a dose-dependent manner in PE mice. In addition, our results showed that AAT injection exhibited an anti-oxidative stress role by significantly reducing PE mediated-upregulation of ROS, MMP9 and MDA, and increasing the levels of SOD, eNOS, and GPx with increased dosage of AAT. Furthermore, we found that AAT injection inactivated PE mediated activation of PAK/STAT1/p38 signaling. These findings were confirmed in human samples. In conclusion, our study suggests that exogenous AAT injection increases the antioxidants and suppresses oxidative stress, and subsequent prevention of PE development through inactivation of STAT1/p38 signaling. Thus, AAT would become a potential strategy for PE therapy.

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.

Biomarker development for presymptomatic molecular diagnosis of preeclampsia: feasible, useful or even unnecessary?

The past decade saw the advent of a number of promising biomarkers to detect pregnancies at risk for preeclampsia (PE), the foremost being those associated with an imbalance of angiogenic factors. In late pregnancy, these are useful for the detection of imminent cases of PE, while earlier they were more predictive for early- than late-onset PE. This suggests that there may be fundamental differences between the underlying pathology of these two PE forms. Therefore, it is possible that such a biological premise may limit the development of biomarkers that will permit the efficacious detection of both early- and late-onset PE via an analysis of first-trimester maternal blood samples. Consequently, a significant increase in our understanding of the underlying pathology of PE, using a variety of approaches ranging from systems biology to animal models, will be necessary in order to overcome this obstacle.