Increased expression of prostasin contributes to early-onset severe preeclampsia through inhibiting trophoblast invasion

PPARγ Regulates Triclosan Induced Placental Dysfunction

Exposure to the antibacterial agent triclosan (TCS) is associated with abnormal placenta growth and fetal development during pregnancy. Peroxisome proliferator-activated receptor γ (PPARγ) is crucial in placenta development. However, the mechanism of PPARγ in placenta injury induced by TCS remains unknown. Herein, we demonstrated that PPARγ worked as a protector against TCS-induced toxicity. TCS inhibited cell viability, migration, and angiogenesis dose-dependently in HTR-8/SVneo and JEG-3 cells. Furthermore, TCS downregulated expression of PPARγ and its downstream viability, migration, angiogenesis-related genes HMOX1, ANGPTL4, VEGFA, MMP-2, MMP-9, and upregulated inflammatory genes p65, IL-6, IL-1β, and TNF-α in vitro and in vivo. Further investigation showed that overexpression or activation (rosiglitazone) alleviated cell viability, migration, angiogenesis inhibition, and inflammatory response caused by TCS, while knockdown or inhibition (GW9662) of PPARγ had the opposite effect. Moreover, TCS caused placenta dysfunction characterized by the significant decrease in weight and size of the placenta and fetus, while PPARγ agonist rosiglitazone alleviated this damage in mice. Taken together, our results illustrated that TCS-induced placenta dysfunction, which was mediated by the PPARγ pathway. Our findings reveal that activation of PPARγ might be a promising strategy against the adverse effects of TCS exposure on the placenta and fetus.

Increased expression of lncRNA SNHG7 promotes the cell viability, migration, and invasion in pre-eclampsia via modulating the miR-214-5p/TWIST1 axis

PURPOSE

This study is aimed to elucidate the molecular mechanism of lncRNA SNHG7 on pre-eclampsia (PE).

METHODS

The expression of SNHG7, miR-214-5p and TWIST1 in PE placental tissues was detected by qRT-PCR. The regulatory mechanism of SNHG7/miR-214-5p/TWIST1 axis on PE was determined using MTT, wound healing, transwell invasion, and western blot assays.

RESULTS

In PE pregnancies, SNHG7 and TWIST1 were decreased, while miR-214-5p was increased.The elevated miR-214-5p and decreased TWIST1 partly eliminated the promoting effects of SNHG7 up-regulation on the viability and metastasis of JEG-3 cells.

CONCLUSIONS

Up-regulated SNHG7 protects against PE through modulating the miR-214-5p/TWIST1 axi.

Implications for preeclampsia: hypoxia-induced Notch promotes trophoblast migration

In the first trimester of human pregnancy, low oxygen tension or hypoxia is essential for proper placentation and placenta function. Low oxygen levels and activation of signaling pathways have been implicated as critical mediators in the promotion of trophoblast differentiation, migration, and invasion with inappropriate changes in oxygen tension and aberrant Notch signaling both individually reported as causative to abnormal placentation. Despite crosstalk between hypoxia and Notch signaling in multiple cell types, the relationship between hypoxia and Notch in first trimester trophoblast function is not understood. To determine how a low oxygen environment impacts Notch signaling and cellular motility, we utilized the human first trimester trophoblast cell line, HTR-8/SVneo. Gene set enrichment and ontology analyses identified pathways involved in angiogenesis, Notch and cellular migration as upregulated in HTR-8/SVneo cells exposed to hypoxic conditions. DAPT, a γ-secretase inhibitor that inhibits Notch activation, was used to interrogate the crosstalk between Notch and hypoxia pathways in HTR-8/SVneo cells. We found that hypoxia requires Notch activation to mediate HTR-8/SVneo cell migration, but not invasion. To determine if our in vitro findings were associated with preeclampsia, we analyzed the second trimester chorionic villous sampling (CVS) samples and third trimester placentas. We found a significant decrease in expression of migration and invasion genes in CVS from preeclamptic pregnancies and significantly lower levels of JAG1 in placentas from pregnancies with early-onset preeclampsia with severe features. Our data support a role for Notch in mediating hypoxia-induced trophoblast migration, which may contribute to preeclampsia development.

Cys-peptide mediates the protective role in preeclampsia-like rat and cell models

OBJECTIVE

The present study was designed to investigate whether the novel peptide cysteine-based peptide (Cys-peptide) had protective effects on preeclamptic animal and cell models.

METHODS

We investigated effects of Cys-peptide on (1) preeclamptic symptoms (e.g. hypertension, proteinuria, fetal growth restriction (FGR)) in preeclampia-like rat models induced by lipopolysaccharides (LPS), (2) TNFα-induced cytotoxicity of human umbilical vascular endothelial cells (HUVECs) and HTR-8 cells (an immortalised human trophoblast cell line), (3) endothelial dysfunction and injured angiogenesis, (4) migration and invasion of trophoblast cells induced by TNFα.

RESULTS

Cys-peptide ameliorated LPS-induced hypertension, proteinuria and FGR and other PE symptoms in preeclampia-like rat models. In addition, Cys-peptide attenuated TNFα-induced cytotoxicity by decreasing soluble fms-like tyrosine kinase-1 (sFlt-1), endothelin-1 (ET-1) and tissue plasminogen activator (tPA) mRNA expression in both cells. Furthermore, Cys-peptide restored endothelial dysfunction and rescued angiogenesis caused by TNFα in vitro. Importantly, Cys-peptide could reverse insufficient ability to invade and migrate of trophoblast cells.

CONCLUSIONS

These results suggest Cys-peptide can play beneficial roles in preeclampsia-like rat and cell models. Therefore, we propose that Cys-peptide is probably a novel therapeutic candidate for PE.

p57KIP2‑mediated inhibition of human trophoblast apoptosis and promotion of invasion in vitro

Placental hypoxia serves a role in the early stages of normal pregnancy and is involved in the pathophysiology of preeclampsia. Previously, it was suggested that p57kinase inhibitory protein (KIP)2 regulates the cell cycle during embryogenesis and apoptosis. Recent evidence has indicated that p57KIP2 is increased in preeclamptic placentas and absence of p57KIP2 induces preeclampsia‑type symptoms in rats. However, effects of p57KIP2 on apoptosis under hypoxic conditions remain to be elucidated. In the present study, HTR‑8/SVneo trophoblasts were cultured under hypoxic conditions (2% O2). Knockdown using small interfering (si)RNA and overexpression of p57KIP2 were utilized to explore the biological function of p57KIP2 in apoptosis and cell function in vitro. Furthermore, expression of p57KIP2 and apoptosis were evaluated by western blotting, flow cytometry and TUNEL assays, and the response of trophoblasts to hypoxia and the role of p57KIP2 in trophoblast migration and invasion was assessed. The role of p57KIP2 in the JNK signaling pathway in HTR‑8/SVneo trophoblasts was further studies. In vitro, protein expression of p57KIP2 was increased in HTR‑8/SVneo cells exposed to 2% O2. Exogenous p57KIP2 overexpression significantly decreased the expression of pro‑apoptosis proteins, including p53, Bax and cleaved caspase3, under hypoxic conditions for 24 h. In addition, knockdown of p57KIP2 increased the response to apoptosis following hypoxia for 24 h. The present study revealed that overexpression of p57KIP2 decreased the levels of phosphorylated‑JNK. JNK inhibitor treatment combined with the overexpression of p57KIP2 significantly decreased the levels of apoptosis and increased cell invasion and migration. Taken together, p57KIP2 knockdown significantly increased apoptosis in HTR‑8/SVneo cells exposed to 2% O2, whereas overexpression of p57KIP2 had opposite effects, mediated by the JNK/stress activated protein kinase (SAPK) signaling pathway. The results indicated that hypoxia‑induced expression of p57KIP2 promoted trophoblast migration and invasion by mediating the JNK/SAPK signaling pathway, which is crucial during placentation. These results may provide a novel molecular mechanism to understand the involvement of p57KIP2 in the pathogenesis of preeclampsia.

Role of proteases in dysfunctional placental vascular remodelling in preeclampsia

Preeclampsia is a syndrome characterised by vascular dysfunction, impaired angiogenesis, and hypertension during pregnancy. Even when the precise pathophysiology of preeclampsia remains elusive, impaired vascular remodelling and placental angiogenesis in the placental villi and defective trophoblast invasion of the uterus are proposed as crucial mechanisms in this syndrome. Reduced trophoblast invasion leads to reduced uteroplacental blood flow and oxygen availability and increased oxidative stress. These phenomena trigger the release of soluble factors into the maternal and foetoplacental circulation that are responsible of the clinical features of preeclampsia. New blood vessels generation as well as vascular remodelling are mechanisms that require expression and activity of different proteases, including matrix metalloproteases, a-disintegrin and metalloproteases, and a-disintegrin and metalloprotease with thrombospondin motifs. These proteases exert proteolysis of the extracellular matrix. Additionally, cathepsins, a family of proteolytic enzymes, are primarily located in lysosomes but are also released by cells to the extracellular space. This review focuses on the role that these proteases play in the regulation of the uterine trophoblast invasion and the placental vascular remodelling associated with preeclampsia.

Long non-coding RNA TUG1 regulates the migration and invasion of trophoblast-like cells through sponging miR-204-5p

Preeclampsia (PE) is a leading cause of maternal and perinatal death. Accumulated evidence suggests that many long non-coding RNAs (lncRNAs) are abnormally expressed in placentas from PE patients, and they may play functional roles in the development of PE. The present study aimed to investigate the functional role TUG1 in PE and explore the potential molecular mechanisms. Clinically, the expression of TUG1 in placental tissues from PE and normal controls was determined. In vitro, human trophoblast HTR-8/SVneo and JAR cells were employed for loss or gain-of-function assays. Our results demonstrate that TUG1 was downregulated in PE placental tissues compared with normal controls. Moreover, downregulation of TUG1 inhibited the migration and invasion of trophoblast-like cells. Bioinformatics analysis and functional assays showed that TUG1 interacted with miR-204-5p and negatively regulated the expression and function of miR-204-5p in trophoblast cells. Furthermore, TUG1-mediated migration and invasion of trophoblast cells was regulated by miR-204-5p. Together, our results suggested that TUG1 regulates trophoblast migration and invasion partly through sponging miR-204-5p, and the TUG1/miR-204-5p axis could be a potential therapeutic target for the treatment of PE.

ANGPTL4 mediates the protective role of PPARγ activators in the pathogenesis of preeclampsia

Peroxisome proliferator-activated receptor γ (PPARγ) has been shown to be a therapeutic target for preeclampsia (PE). Angiopoietin-like protein 4 (ANGPTL4) is a multifunctional secretory protein involved in regulating lipid metabolism and angiogenesis in various tissues. However, the expression of PPARγ and ANGPTL4 and their interaction in PE remain elusive. Here we showed that PPARγ agonist rosiglitazone upregulated the expression and secretion of ANGPTL4 in a dose-dependent manner in HTR8/SVneo cells, human umbilical vein endothelial cells (HUVECs) and placental explants. More importantly, we confirmed that the PPARγ/retinoid X receptor α heterodimer specifically binds to the ANGPTL4 promoter region and enhances its transcriptional activity. In addition, the levels of ANGPTL4 and PPARγ activators in the serum and their expression in placental tissues were significantly reduced in preeclamptic patients compared with normal pregnant subjects. Furthermore, functional studies demonstrated that ANGPTL4 mediates the facilitative effects of the PPARγ agonist on the survival, proliferation, migration and invasion of HTR8/SVneo cells, placental explants outgrowth and angiogenesis in HUVECs. Taken together, our results suggest that ANGPTL4 is a potential target gene for PPARγ and mediates the protective role of PPARγ activators in the pathogenesis of PE.

Notch2 and Notch3 suppress the proliferation and mediate invasion of trophoblast cell lines

Notch signaling pathways play important roles in cell fate and many diseases, including preeclampsia, the dysregulation of which may be the main cause of maternal mortality. This study aimed to investigate the roles of Notch2 and Notch3 in proliferation and invasion in trophoblast cell lines (BeWo and JAR). Small hairpin RNAs targeting Notch2/Notch3 and Notch2/Notch3-overexpression vectors were designed, constructed and transfected into BeWo and JAR cells. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were then used to detect Notch2 and Notch3 mRNA and protein levels, and confirm the efficiency of silence and overexpression. Flow cytometry assays were conducted to evaluate the cell cycle of the two cell lines, and transwell assays were used to detect migration and invasion. Western blot analysis was also performed to show the alteration of the cell lines' physiological activities at protein level.When Notch2 was downregulated in BeWo cells, proliferation was dramatically promoted, while migration and invasion were significantly inhibited. When Notch2 was upregulated in JAR cells, proliferation was inhibited, but migration and invasion were promoted. After overexpression of Notch3 in BeWo cells, proliferation was downregulated, but migration and invasion were both upregulated. By contrast, the silencing of Notch3 expression in JAR cells significantly enhanced proliferation, but suppressed migration and invasion. These data indicated that Notch2 and Notch3 mediate the invasion and migration of BeWo and JAR cells, and may play a potential role in early onset severe preeclampsia.

Transthyretin regulates the migration and invasion of JEG-3 cells

Preeclampsia (PE) is a pregnancy-specific disorder characterized by new-onset hypertension and proteinuria that occurs after 20 weeks of gestation. It involves several organs and continues to be a leading cause of maternal and perinatal morbidity and mortality worldwide. Shallow trophoblast invasion is a common pathological feature of PE. Transthyretin (TTR) is a 56-kDa homotetrameric protein that binds thyroid hormone and retinol binding protein. Dysregulated TTR expression has been found in cases of PE. The aim of the present study was to determine the functional role of TTR in the migration and invasion of JEG-3 choriocarcinoma cells. JEG-3 cells were transfected with a plasmid construct expressing TTR (pCMV-Myc-TTR) or an empty plasmid (pCMV-Myc). Cell migration and invasion capacities were assessed by Transwell migration and invasion assays, respectively. These experiments demonstrated that TTR overexpression significantly increased the migration and invasion potential of JEG-3 cells. Matrix metalloproteinases (MMPs) are a family of zinc-containing endopeptidases capable of degrading a wide range of extracellular matrix components. Western blot analysis revealed that TTR overexpression resulted in significantly increased levels of MMP2 and MMP9 in JEG-3 cells. In conclusion, our findings suggest an important role for TTR in regulating trophoblast invasion and migration, representing a possible underlying pathological and molecular mechanisms of PE.

Distinct expression profiles of lncRNAs between early-onset preeclampsia and preterm controls

Early-onset preeclampsia (EOPE), which is the most severe form of the syndrome, confers a high risk of neonatal morbidity and perinatal death. We aim to study the roles of long non-coding RNAs (lncRNAs) in the pathogenesis of early-onset preeclampsia (EOPE). Therefore, we examined the expression profiles of lncRNAs between early-onset preeclampsia and preterm controls using microarray analysis. Quantitative real-time PCR (qRT-PCR) was performed to verify the selected differentially expressed lncRNAs. In total, we identified 15,646 upregulated and 13,178 downregulated lncRNAs in the placenta of EOPE patients compared to the preterm controls. Gene ontology and pathway analysis revealed that compared to the preterm controls, many of the processes over-represented in the EOPE patients were related to cell migration and cell motility. A selection of the differentially expressed lncRNA transcripts was confirmed using qRT-PCR, particularly RP11-465L10.10, which is associated with the MMP9 gene. These data may offer a background/reference resource for future functional studies of lncRNAs related to EOPE.

IFI16 mediates soluble Flt-1 and endoglin production by trophoblast cells

OBJECTIVES

Preeclampsia is a serious pregnancy-specific hypertensive syndrome that is characterized by widespread maternal endothelial dysfunction. Previous studies have shown that increased levels of circulating cell-free fetal DNA in women with preeclampsia correspond to the degree of disease severity; however, it is unknown whether this DNA is a key signal that contributes to the development of preeclampsia. The detection of DNA is critical to appropriate innate immune responses. The interferon-inducible protein 16 (IFI16) - a member of the HIN-200 family - is an innate immune receptor for intracellular DNA, which is implicated in the control of cell growth, apoptosis, angiogenesis, and immunomodulation; however, its role in preeclampsia remains unresolved. Here, we tested the hypothesis that this DNA can activate IFI16 in the placentas of women with preeclampsia and is sufficient to induce soluble fms-like tyrosine kinase 1 (sFlt-1) and soluble endoglin (sEng) production.

METHODS

We characterized IFI16 in severe preeclamptic placentas and assessed whether DNA increased the release of sFlt-1 and sEng from trophoblast cells and placental explants. Furthermore, we determined whether IFI16 was involved in DNA-induced sFlt-1 and sEng production.

RESULTS

Placental immunoreactivity and protein levels of IFI16 were significantly increased in women with preeclampsia compared to matched control women. Treatment of human trophoblasts with the IFI16 agonist poly(dA:dT) significantly increased IFI16 levels. Furthermore, poly(dA:dT) induced sFlt-1 and sEng production by human trophoblasts in an IFI16-dependent manner.

CONCLUSIONS

We conclude that trophoblast cells respond to cell-free fetal DNA through the IFI16 receptor, resulting in the production of the preeclampsia-related antiangiogenic factors sFlt-1 and sEng.

Ibuprofen regulates the expression and function of membrane-associated serine proteases prostasin and matriptase

BACKGROUND

The glycosylphosphatidylinositol-anchored extracellular membrane serine protease prostasin is expressed in normal bladder urothelial cells. Bladder inflammation reduces prostasin expression and a loss of prostasin expression is associated with epithelial-mesenchymal transition (EMT) in human bladder transitional cell carcinomas. Non-steroidal anti-inflammatory drugs (NSAIDs) decrease the incidence of various cancers including bladder cancer, but the molecular mechanisms underlying the anticancer effect of NSAIDs are not fully understood.

METHODS

The normal human bladder urothelial cell line UROtsa, the normal human trophoblast cell line B6Tert-1, human bladder transitional cell carcinoma cell lines UM-UC-5 and UM-UC-9, and the human breast cancer cell line JIMT-1 were used for the study. Expression changes of the serine proteases prostasin and matriptase, and cyclooxygenases (COX-1 and COX-2) in these cells following ibuprofen treatments were analyzed by means of reverse-transcription/quantitative polymerase chain reaction (RT-qPCR) and immunoblotting. The functional role of the ibuprofen-regulated prostasin in epithelial tight junction formation and maintenance was assessed by measuring the transepithelial electrical resistance (TEER) and epithelial permeability in the B6Tert-1 cells. Prostasin's effects on tight junctions were also evaluated in B6Tert-1 cells over-expressing a recombinant human prostasin, silenced for prostasin expression, or treated with a functionally-blocking prostasin antibody. Matriptase zymogen activation was examined in cells over-expressing prostasin.

RESULTS

Ibuprofen increased prostasin expression in the UROtsa and the B6Tert-1 cells. Cyclooxygenase-2 (COX-2) expression was up-regulated at both the mRNA and the protein levels in the UROtsa cells by ibuprofen in a dose-dependent manner, but was not a requisite for up-regulating prostasin expression. The ibuprofen-induced prostasin contributed to the formation and maintenance of the epithelial tight junctions in the B6Tert-1 cells. The matriptase zymogen was down-regulated in the UROtsa cells by ibuprofen possibly as a result of the increased prostasin expression because over-expressing prostasin leads to matriptase activation and zymogen down-regulation in the UROtsa, JIMT-1, and B6Tert-1 cells. The expression of prostasin and matriptase was differentially regulated by ibuprofen in the bladder cancer cells.

CONCLUSIONS

Ibuprofen has been suggested for use in treating bladder cancer. Our results bring the epithelial extracellular membrane serine proteases prostasin and matriptase into the potential molecular mechanisms of the anticancer effect of NSAIDs.

Oxidative Stress Alters miRNA and Gene Expression Profiles in Villous First Trimester Trophoblasts

The relationship between oxidative stress and miRNA changes in placenta as a potential mechanism involved in preeclampsia (PE) is not fully elucidated. We investigated the impact of oxidative stress on miRNAs and mRNA expression profiles of genes associated with PE in villous 3A first trimester trophoblast cells exposed to H₂O₂ at 12 different concentrations (0-1 mM) for 0.5, 4, 24, and 48 h. Cytotoxicity, determined using the SRB assay, was used to calculate the IC₅₀ of H₂O₂. RNA was extracted after 4 h exposure to H₂O₂ for miRNA and gene expression profiling. H₂O₂ exerted a concentration- and time-dependent cytotoxicity on 3A trophoblast cells. Short-term exposure of 3A cells to low concentration of H₂O₂ (5% of IC₅₀) significantly altered miRNA profile as evidenced by significant changes in 195 out of 595 evaluable miRNAs. Tool for annotations of microRNAs (TAM) analysis indicated that these altered miRNAs fall into 43 clusters and 34 families, with 41 functions identified. Exposure to H₂O₂ altered mRNA expression of 22 out of 84 key genes involved in dysregulation of placental development. In conclusion, short-term exposure of villous first trimester trophoblasts to low concentrations of H₂O₂ significantly alters miRNA profile and expression of genes implicated in placental development.