Xiaofang Luo

Laminin α4 (LAMA4) expression promotes trophoblast cell invasion, migration, and angiogenesis, and is lowered in preeclamptic placentas.

INTRODUCTION The laminin α4 subunit (LAMA4) has been shown to promote migration, proliferation, and survival of various cell types. This study investigated LAMA4s role in trophoblast cells during placental development. METHODS LAMA4 expression was immunohistochemically assessed in the first trimester and term human placentas. LAMA4 siRNA was applied to silence LAMA4 expression in extravillous explants and HTR8/SVneo cells. Hypoxia-reoxygenation (H/R) conditions were applied to mimic preeclampsia. LAMA4 expression and trophoblast cell invasion, migration, and tube formation (a measure of angiogenesis) were assessed in HTR8/SVneo cells. The p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 was used to study the mechanism underlying LAMA4 activity. LAMA4 promoter methylation was assessed by bisulfite-sequencing polymerase chain reaction (PCR) or methylation-specific PCR. RESULTS LAMA4 levels in preeclamptic placentas were significantly lower than those in controls. LAMA4 silencing significantly inhibited extravillous explant outgrowth as well as HTR8/SVneo cell invasion and migration. H/R conditions significantly lowered LAMA4 expression. Application of either H/R conditions or LAMA4 silencing both significantly decreased HTR8/SVneo cell invasion, migration, and tube formation, decreased MMP2 and MMP9 expression, and increased TIMP2 expression. SB203580 significantly reduced LAMA4 expression. LAMA4 silencing significantly decreased p-p38, p-c-Jun N-terminal kinase (JNK), and p-extracellular signal-regulated kinase (ERK) expressions; by contrast, H/R conditions induced significant upregulation of p-p38 and p-ERK but decreased p-JNK. LAMA4 promoter methylation was not significantly altered in preeclamptic placentas compared to controls. CONCLUSIONS LAMA4 expression is lowered in preeclamptic placentas and promotes trophoblast cell invasion, migration, and angiogenesis. H/R conditions decrease LAMA4 expression and appear to decouple the positive relationship between LAMA4 expression and p38 and ERK activation.

Expression of Gadd45α in human early placenta and its role in trophoblast invasion

OBJECTIVES Well-controlled trophoblast migration and invasion at the maternal-foetal interface are crucial events for normal placentation and successful pregnancy. Growing evidence has revealed that growth arrest and DNA damage-inducible 45 alpha (Gadd45α) participates in tumour migration and invasion as a tumour suppressor. However, the expression and function of Gadd45α in trophoblasts is unknown. This study aimed to determine the Gadd45α expression and function in the human first trimester placenta and identify the underlying mechanisms. METHODS The expression of Gadd45α in human first trimester placenta was determined using immunohistochemistry. HTR8/SVneo cell line was used to investigate the effects of Gadd45α on proliferation, apoptosis, migration/invasion, matrix metalloproteinase (MMP)2/9 activities, and tissue inhibitor of metalloproteinase (TIMP)1/2 expression using cell proliferation assays, flow cytometric analysis, transwell migration/invasion assays, gelatin gel zymography, and western blotting, respectively. Moreover, a placental villous explant model was employed to verify its functions in placentation. RESULTS Gadd45α was strongly expressed in syncytiotrophoblasts and trophoblast columns of human placental villi, extravillous trophoblast cells and glandular epithelium within the maternal decidua. Gadd45α knockdown significantly promoted migration and invasion of HTR8/SVneo cells, whereas it did not affect cell proliferation or apoptosis. Silencing Gadd45α also enhanced trophoblast outgrowth and migration in placental explants. These effects were related to increased activities of MMP2/9 and the decreased expression of TIMP1/2. DISCUSSION AND CONCLUSION Gadd45α may be involved in human trophoblast migration and invasion and may function as an important negative regulator at the foetal-maternal interface during early pregnancy by directly or indirectly regulating MMP2/9 activities.

Oxidative stress-induced C/EBPβ inhibits β-catenin signaling molecule involving in the pathology of preeclampsia.

INTRODUCTION Oxidative stress-induced trophoblast cell dysfunction is a major pathology in preeclampsia (PE). Recently, CCAAT/enhancer binding protein beta (C/EBPβ) has been investigated as a tumor suppressor that participates in tumor invasion. However, the function of C/EBPβ in trophoblast cells remains unknown. Our study was designed to detect the expression of C/EBPβ in the preeclamptic placenta and to identify the underlying mechanisms of oxidative stress. METHODS Human placental tissues with PE were collected. The expression of C/EBPβ and β-catenin were detected. Human first trimester extravillous trophoblast cell (HTR8/SVneo) line exposed to hypoxia/reoxygenation (H/R) was employed as an oxidative stress model in vitro to investigate the effects of C/EBPβ on invasion and the expression of β-catenin. Moreover, first trimester-derived placental villous explants were used to verify the effects of C/EBPβ and β-catenin in placentation. RESULTS In preeclamptic placentas, C/EBPβ was overexpressed and β-catenin was decreased. In addition, C/EBPβ was found to have increased expression in H/R-treated HTR8/SVneo cells and villous explants. C/EBPβ knockdown and β-catenin activation could significantly promote the invasion of HTR8/SVneo cells, enhance the outgrowth and migration in villous explants and inhibit the excessive generation of intracellular ROS. These findings might be related to the increased activities of MMP-2/9 and the decreased expression of TIMP-1/2. Meanwhile, C/EBPβ knockdown remarkably increased the expression of β-catenin. DISCUSSION We hypothesize that the oxidative stress-induced overexpression of C/EBPβ might influence the activity of MMPs by regulating the Wnt/β-catenin signaling pathway to affect the invasion of trophoblast cells, which then participate in the pathogenesis of preeclampsia.

High-intensity focused ultrasound treatment of placenta accreta after vaginal delivery: a preliminary study.

To evaluate the safety and efficiency of high‐intensity focused ultrasound (HIFU) in the treatment of placenta accreta after vaginal delivery.

SRC-3 Plays a Critical Role in Human Umbilical Vein Endothelial Cells by Regulating the PI3K/Akt/mTOR Pathway in Preeclampsia:

Preeclampsia (PE) is currently thought to be characterized by oxidative stress which may lead to endothelial dysfunction. The normal function of vascular endothelium is essential to vascular homeostasis. Previous studies have shown that steroid receptor coactivator 3 (SRC-3) interacts with estrogen receptors (ERs) which are involved in the vasoprotective effects of estrogen and is also associated with cell migration, invasion, and inflammation; however, its role in PE remains unclear. The main purpose of this study is to identify the role of SRC-3 in the function of human umbilical vein endothelial cells (HUVECs) during the development of PE. Our study demonstrated that the expression of SRC-3 was significantly decreased in PE placentas compared to normal placentas. Additionally, lentivirus short hairpin RNA against SRC-3 and hypoxia/reoxygenation treatments attenuated migration and tube formation abilities and enhanced HUVEC apoptosis. Furthermore, we detected possible downstream in the PI3K/Akt/mammalian target of rapamycin (mTOR) signal pathway activity, which is involved in SRC-3-mediated HUVEC function. Our data suggest that oxidative stress plays a crucial role in controlling SRC-3 expression, which influences the migration and tube formation abilities of endothelial cells through the PI3K/Akt/mTOR signaling pathways. This action may then result in PE pathogenesis.

The Role of MGAT5 in Human Umbilical Vein Endothelial Cells Possible Relevance to the Pathological Mechanism of Preeclampsia

Preeclampsia (PE) is associated with shallow invasion of the trophoblast and insufficient remodeling of the uterine spiral artery. Glycosylation reactions are catalyzed by glycosyltransferases including N-acetylglucosaminyltransferase V (MGAT5) and accumulating evidence suggests that MGAT5 is correlated with the migration, proliferation, and survival of various cell types. Our previous study confirmed that MGAT5 is a negative regulator of trophoblast migration and invasion via the direct or indirect inhibition of matrix metalloproteinase 2/9 activity. The primary purpose of this study is to investigate the role of MGAT5 in the function of human umbilical vein endothelial cells (HUVECs) during the development of PE. We observed that MGAT5 was specifically localized within the decidual cells and endothelial cells in maternal decidual tissues. The expression of MGAT5 was elevated in PE placentas compared with the normal control placentas. Moreover, the expression of MGAT5 was increased in hypoxia–reoxygenation (H/R)-treated HUVECs. The knockdown of MGAT5 and PD98059 treatment significantly enhanced cell migration in vitro, promoted tube formation capacity, and inhibited apoptosis in H/R-exposed HUVECs. Our data suggest that oxidative stress induces the overexpression of MGAT5 via the regulation of the focal adhesion kinase–extracellular signal-regulated kinase signaling pathway, which, in turn, affects the function of endothelial cells, which then participates in the pathogenesis of PE.Preeclampsia (PE) is associated with shallow invasion of the trophoblast and insufficient remodeling of the uterine spiral artery. Glycosylation reactions are catalyzed by glycosyltransferases including N-acetylglucosaminyltransferase V (MGAT5) and accumulating evidence suggests that MGAT5 is correlated with the migration, proliferation, and survival of various cell types. Our previous study confirmed that MGAT5 is a negative regulator of trophoblast migration and invasion via the direct or indirect inhibition of matrix metalloproteinase 2/9 activity. The primary purpose of this study is to investigate the role of MGAT5 in the function of human umbilical vein endothelial cells (HUVECs) during the development of PE. We observed that MGAT5 was specifically localized within the decidual cells and endothelial cells in maternal decidual tissues. The expression of MGAT5 was elevated in PE placentas compared with the normal control placentas. Moreover, the expression of MGAT5 was increased in hypoxia-reoxygenation (H/R)-treated HUVECs. The knockdown of MGAT5 and PD98059 treatment significantly enhanced cell migration in vitro, promoted tube formation capacity, and inhibited apoptosis in H/R-exposed HUVECs. Our data suggest that oxidative stress induces the overexpression of MGAT5 via the regulation of the focal adhesion kinase-extracellular signalregulated kinase signaling pathway, which, in turn, affects the function of endothelial cells, which then participates in the pathogenesis of PE.

Triethylenetetramine Synergizes with Pharmacologic Ascorbic Acid in Hydrogen Peroxide Mediated Selective Toxicity to Breast Cancer Cell

Breast cancer is characterized by overexpression of superoxide dismutase (SOD) and downregulation of catalase and more resistance to hydrogen peroxide (H2O2) than normal cells. Thus, relatively high H2O2 promotes breast cancer cell growth and proliferation. However, excessive intracellular H2O2 leads to death of breast cancer cells. In cancer cells, high level ascorbic acid (Asc) is able to be autoxidized and thus provides an electron to oxygen to generate H2O2. In the present study, we demonstrated that triethylenetetramine (TETA) enhances Asc autoxidation and thus elevates H2O2 production in MCF-7 cells. Furthermore, Asc/TETA combination significantly impaired cancer cell viability, while having much milder effects on normal cells, indicating Asc/TETA could be a promising therapy for breast cancer. Moreover, SOD1 and N-acetyl-L-cysteine failed to improve MCF-7 cells viability in the presence of Asc/TETA, while catalase significantly inhibited the cytotoxicity of Asc/TETA to breast cancer cells, strongly suggesting that the selective cytotoxicity of Asc/TETA to cancer cells is H2O2-dependent. In addition, Asc/TETA induces RAS/ERK downregulation in breast cancer cells. Animal studies confirmed that Asc/TETA effectively suppressed tumor growth in vivo. In conclusion, TETA synergizes pharmacologic Asc autoxidation and H2O2 overproduction in breast cancer cells, which suppresses RAS/ERK pathway and results in apoptosis.

Metabolic Biomarkers of Monochorionic Twins Complicated With Selective Intrauterine Growth Restriction in Cord Plasma and Placental Tissue

The selective intrauterine growth restriction (sIUGR) of monochorionic diamniotic (MCDC) twins causes phenotypic growth discordance, which is correlated with metabolomic pertubations. A global, untargeted identification of the metabolic fingerprint may help elucidate the etiology of sIUGR. Umbilical cord blood and placentas collected from 15 pairs of sIUGR monochorionic twins, 24 pairs of uncomplicated twins, and 14 singletons diagnosed with intrauterine growth restriction (IUGR) were subjected to gas chromatography-mass spectrometry based metabolomic analyses. Supervised multivariate regression analysis and pathway analysis were performed to compare control twins with sIUGR twins. A generalized estimating equation (GEE) model was utilized to explore metabolic differences within sIUGR co-twins. Linear logistic regression was applied to screen metabolites that significantly differed in concentration between control twins and sIUGR twins or IUGR singletons. Umbilical cord blood demonstrated better global metabolomic separation of sIUGR and control twins compared to the placenta. Disrupted amino acid and fatty acid metabolism as well as high levels of exposure to environmental xenobiotics were associated with sIUGR. The metabolic abnormalities in MCDA twins suggested that in utero growth discordance is caused by intrauterine and extrauterine environmental factors, rather than genetics. Thus, this study provides new therapeutic targets and strategies for sIUGR management and prevention.

QSOX1 regulates trophoblastic apoptosis in preeclampsia through hydrogen peroxide production.

Abstract Objective: Oxidative stress plays a significant role in the pathogenesis of preeclampsia (PE), by inducing trophoblast cell death and consequent placental dysfunction. Quiescin sulfhydryl oxidase 1 (QSOX1) is upregulated in many types of cancer cells; it promotes disulfide bond formation as well as hydrogen peroxide (H2O2) production. The aims of present study are to investigate the expression pattern of QSOX1 in placentae of pregnancies complicated by PE and the role of QSOX1 in the regulation of trophoblastic function, thus providing in-depth understanding of the putative involvement of QSOX1 in the development of PE. Methods: Human term placenta from normal pregnancies and from pregnancies complicated by PE was collected to measure QSOX1 expression and H2O2 levels. Down-regulation of QSOX1 in HTR-8/SVneo cells was achieved by siRNA interference. An in vitro cellular PE model was generated by hypoxic incubation. Protein expression levels were assessed by Western blotting, and H2O2 levels were determined in the cell culture medium as well as in the cell lysate. Trophoblast apoptosis was evaluated by TUNEL staining. Results: QSOX1 was overexpressed in the PE placenta. Inhibition of QSOX1 expression in HTR-8/SVneo cells attenuated cell apoptosis and intracellular H2O2 levels. Hypoxia-induced QSOX1 expression in HTR-8/SVneo cells and led to apoptosis of HTR-8/SVneo cells, and knock-down of QSOX1 rescued hypoxia-induced trophoblast apoptosis. Conclusions: Hypoxia-induced upregulation of QSOX1 and a consequent elevation in intracellular H2O2 increased apoptosis in placentae of pregnancies complicated by PE.

IL-27 induces a pro-inflammatory response in human fetal membranes mediating preterm birth

Abstract Inflammation at the maternal‐fetal interface has been shown to be involved in the pathogenesis of preterm birth. Interleukin 27 (IL‐27), a heterodimeric cytokine, is known to mediate an inflammatory response in some pregnancy complications. In this study, we aimed to determine whether IL‐27 could induce an inflammatory reaction at the maternal‐fetal interface that would mediate the onset of preterm birth. We found elevated expression of IL‐27 in human peripheral serum and elevated expression of its specific receptor (wsx‐1) on fetal membranes in cases of preterm birth. Moreover, the release of inflammatory markers (CXCL10, IFN‐&ggr;, MCP‐1, IL‐6, IL‐1&bgr; and TNF‐&agr;), especially CXCL10, was markedly augmented upon stimulation of IL‐27 in the fetal membranes. Additionally, IL‐27 and IFN‐&ggr; cooperated to amplify the expression of CXCL10 in the fetal membranes. Moreover, the production of CXCL10 was increased in IL‐27‐treated fetal membrane through JNK, PI3K or Erk signaling pathways. Finally, MMP2 and MMP9 were activated by IL‐27 in human fetal membranes, which may be related to the onset of preterm premature rupture of membranes (pPROM). In conclusion, for the first time, we reported that the aberrant expression of IL‐27 could mediate an excessive inflammatory response in fetal membranes through the JNK, PI3K or Erk signaling pathways, which contributes to preterm birth. HighlightsAberrant expression of IL‐27 in peripheral serum and its specific receptor wsx‐1 in preterm birth women are observed.IL‐27 enhances the release of IL‐1&bgr;, IL‐6, TNF‐&agr;, IFN‐&ggr;, CXCL10 and MCP‐1 in human fetal membranes.IL‐27 amplifies the expression of CXCL10 in synergy with IFN‐&ggr; in human fetal membranes.Molecular inhibitors of c‐JNK, PI3K and/or Erk signaling pathways attenuates production of CXCL10 in IL‐27‐treated fetal membrane.IL‐27 activates MMP2 and MMP9 in human fetal membranes.IL‐27 may play a potential role in predicting preterm birth.