The protective effect of apolipoprotein in models of trophoblast invasion and preeclampsia

Exploration of Serum lipid levels during twin pregnancy

Objective: This study aims to characterize changes in serum lipid levels throughout twin pregnancies and explore the relationship between lipid levels and gestational diabetes mellitus (GDM) and hypertensive disorders complicating pregnancy (HDCP).Methods: We retrospectively studied 297 twin pregnancies of women who received regular prenatal care and delivered at the Beijing Obstetrics and Gynecology Hospital over a period of two years. Demographic and medical data of the participants were collected by questionnaires and medical records review. Serum lipid levels were measured in the first trimester (6-13 weeks), second trimester (24-28 weeks), and third trimester (34-37 weeks). A multivariate regression model was constructed to examine the association between lipid levels and pregnancy complications. A decision tree was used to explore the relationship between early serum lipid glucose levels and GDM and HDCP in twin pregnancies.Results: Triglyceride (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels increased significantly from the first trimester to the third trimester, with the exception of high-density lipoprotein cholesterol (HDL-C), which decreased in the third trimester in twin pregnancies (p < 0.001). The levels of TC in the GDM and HDCP group were significantly elevated compared to those in the normal group in early pregnancies (p < 0.05, p < 0.05). In the second trimester, TG in the HDCP group was substantially higher than that in the normal group (p = 0.01). In the third trimester, LDL-C and HDL-C levels in the GDM group are significantly lower than that in the normal group (p < 0.05, p < 0.05). After adjusting for confounders, body mass index (BMI) is independently associated with GDM (odds ratio [OR] = 1.129, 95% confidence interval [CI]: 1.007-1.266) and HDCP(odds ratio [OR] = 1.170, 95% confidence interval [CI]: 1.031-1.329). The variation amplitude of HDL-C in the third trimester is related to the occurrence of GDM and HDCP(GDM:OR = 0.271, 95%CI: 0.095-0.778; HDCP: OR =0.249, 95% CI: 0.075-0.823). TG and TC levels in DCDA twins were significantly higher than that in MCDA twins in the first trimester(TG: p < 0.05, TC: p < 0.05). In the decision tree model for GDM, fasting blood glucose in the first trimester (FBG), TC, and pre-pregnancy BMI were identified as important nodes, while in the HDCP model, pre-pregnancy BMI, TC, and TG were key nodes.Conclusion: Serum lipid levels in twin pregnancies increase gradually during pregnancy. BMI is independently associated with the occurrence of GDM and HDCP. HDL-C may serve as a protective factor for GDM and HDCP. The predictive effect of early blood lipid on GDM and HDCP in twin pregnancy needs further study.

Death receptor 3 is involved in preeclampsia through regulating placental trophoblast cell physiology by inactivating the PI3K/AKT pathway

BACKGROUND

Preeclampsia (PE) is a pregnancy related disease that affects about 5% of pregnancies. Death receptor 3 (DR3) expression is significantly elevated in both placental tissue and plasma of PE patients. However, whether DR3 was involved in trophoblasts in pathogenesis of PE are not well elucidated.

OBJECTIVE

Our research was designed to illustrate the biological roles of DR3 in placental trophoblasts, as well as explain its relevant mechanisms.

METHODS

HTR-8/SVneo cells viability, migration, invasion, and apoptosis were assessed using MTT, Transwell assay, and flow cytometry analysis, respectively. Levels of DR3, PI3K, and AKT in HTR-8/SVneo cells were analyzed via reverse transcription-quantitative polymerase chain reaction assay. Western blot analysis was utilized to assess DR3, p-PI3K, p-AKT, PI3K, and AKT protein expression.

RESULTS

Upregulation of DR3 obviously inhibited HTR-8/SVneo cells viability, migration, and invasion, as well as promoted HTR-8/SVneo cells apoptosis, as opposed to the control-plasmid group. We also found that DR3-plasmid enhanced cleaved-caspase3 expression, reduced p-PI3K and p-AKT protein expression, and p-PI3K/PI3K or p-AKT/AKT ratio in HTR-8/SVneo cells. Importantly, IGF-1, a PI3K/AKT signaling pathway agonist, partially reversed the effects of DR3-plasmid on the cell viability, migration, invasion, apoptosis, and PI3K/AKT signal pathway in HTR-8/SVneo cells.

CONCLUSION

DR3 was involved in PE through regulating placental trophoblast cell physiology via PI3K/AKT pathway, which might be a promising therapeutic target for PE therapy.

The Influence of Nicotine on Trophoblast-Derived Exosomes in a Mouse Model of Pathogenic Preeclampsia

Preeclampsia (PE) is a serious complication of pregnancy with a pathogenesis that is not fully understood, though it involves the impaired invasion of extravillous trophoblasts (EVTs) into the decidual layer during implantation. Because the risk of PE is actually decreased by cigarette smoking, we considered the possibility that nicotine, a critical component of tobacco smoke, might protect against PE by modifying the content of exosomes from EVTs. We investigated the effects of nicotine on our PE model mouse and evaluated blood pressure. Next, exosomes were extracted from nicotine-treated extravillous trophoblasts (HTR-8/SVneo), and the peptide samples were evaluated by DIA (Data Independent Acquisition) proteomic analysis following nano LC-MS/MS. Hub proteins were identified using bioinformatic analysis. We found that nicotine significantly reduced blood pressure in a PE mouse model. Furthermore, we identified many proteins whose abundance in exosomes was modified by nicotine treatment of EVTs, and we used bioinformatic annotation and network analysis to select five key hub proteins with potential roles in the pathogenesis or prevention of PE. EVT-derived exosomes might influence the pathogenesis of PE because the cargo delivered by exosomes can signal to and modify the receiving cells and their environment.

The involvement of long noncoding RNA APOA1-AS in the pathogenesis of preeclampsia

OBJECTIVE

Long noncoding RNAs (lncRNAs) are involved in preeclampsia (PE), and apolipoprotein A-1 antisense RNA (APOA1-AS) and has been found to be associated with a number of diseases. Our study aims to understand the involvement of APOA1-AS in PE.

METHODS

Clinically, APOA1-AS expression in early-onset severe PE (EOSPE) patients and healthy controls was detected by real-time quantitative polymerase chain reaction. In vitro experiments were divided into control [coculturing trophoblasts with human uterine microvascular endothelial cells (UtMVECs)], TNF-α [coculturing trophoblasts with UtMVECs treated with tumor necrosis factor-α (TNF-α)], and TNF-α + control siRNA/APOA1-AS siRNA groups (UtMVECs transfected with control siRNA/APOA1-AS siRNA were cocultured with trophoblasts in the presence of TNF-α). The animals were divided into normal group, PE group (PE model was established by administrating nitro-L-arginine methyl ester (L-NAME) in rats), PE + control siRNA group (PE rats were treated with control siRNA), and PE + APOA1-AS siRNA group (PE rats were treated with APOA1-AS siRNA).

RESULTS

Increased APOA1-AS was found in the placental tissues of EOSPE patients. APOA1-AS siRNA abolished the decreased integration of trophoblasts into UtMVEC networks induced by TNF-α. Furthermore, APOA1-AS siRNA improved pregnancy outcomes in PE rats with increased expression of vascular endothelial growth factor, placental growth factor, and fms-like tyrosine kinase receptor (Flt-1) but decreased expression of E-cadherin, intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1).

CONCLUSION

Downregulation of APOA1-AS protected against TNF-α-induced inhibition of trophoblast integration into endothelial networks, thus exerting protective effects against PE rats.

Preexisting hypertension and pregnancy-induced hypertension reveal molecular differences in placental proteome in rodents

Preexisting or new onset of hypertension affects pregnancy and is one of the leading causes of maternal and fetal morbidity and mortality. In certain cases, it also leads to long-term maternal cardiovascular complications. The placenta is a key player in the pathogenesis of complicated hypertensive pregnancies, however the pathomechanisms leading to an abnormal placenta are poorly understood. In this study, we compared the placental proteome of two pregnant hypertensive models with their corresponding normotensive controls: a preexisting hypertension pregnancy model (stroke-prone spontaneously hypertensive rats; SHRSP) versus Wistar-Kyoto and the transgenic RAS activated gestational hypertension model (transgenic for human angiotensinogen Sprague-Dawley rats; SD-PE) versus Sprague-Dawley rats, respectively. Label-free proteomics using nano LC-MS/MS was performed for identification and quantification of proteins. Between the two models, we found widespread differences in the expression of placental proteins including those related to hypertension, inflammation, and trophoblast invasion, whereas pathways such as regulation of serine endopeptidase activity, tissue injury response, coagulation, and complement activation were enriched in both models. We present for the first time the placental proteome of SHRSP and SD-PE and provide insight into the molecular make-up of models of hypertensive pregnancy. Our study informs future research into specific preeclampsia and chronic hypertension pregnancy mechanisms and translation of rodent data to the clinic.

LINC01128 - miR-16 interaction regulates the migration and invasion of human chorionic trophoblast cells

Objective: Pre-eclampsia (PE) is a major complication of pregnancy, but its pathogenesis is unclear. This study explored the role of LINC01128 in the progression of PE, and its interaction with miR-16 on the behaviors of trophoblasts.Methods: The mRNA levels of LINC01128 and miR-16 in placental tissues and HTR-8/SVneo cells were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Cell Counting Kit (CCK)-8, wound healing assay and transwell assay were used to detect proliferation, migration and invasion. E-Cadherin, Vimentin, Matrix metalloproteinase 2 (MMP2) and MMP9 protein expressions were detected by Western blot. The correlation between LINC01128 and miR-16 was determined and verified by starBase and dual-luciferase assay.Results: The expression of LINC01128 was downregulated in PE. Overexpression of LINC01128 promoted LINC01128 expression, cell proliferation, migration, invasion and the expressions of Vimentin, MMP2 and MMP9, but inhibited the expression of E-Cadherin. SiLINC01128 showed opposite effects. MiR-16 interacted with LINC01128, and miR-16 was high-expressed in PE placentae. MiR-16 inhibitor promoted cell proliferation, migration, invasion and related protein expressions, but inhibited the expression of E-Cadherin. However, siLINC01128 inhibited the regulatory effect of miR-16 inhibitor on HTR-8/Svneo cells.Conclusion: LINC01128/miR-16 is involved in HTR-8/SVneo cells by regulating the migration and invasion of human chorionic trophoblast cells.

Genetic markers for preeclampsia in Peruvian women

BACKGROUND

Preeclampsia is a multiorgan disorder associated with maternal and perinatal morbi-mortality. In Peru, incidence is 10% and accounts for 22% of maternal deaths. Genome and genetic epidemiological studies have found an association between preeclampsia and genetic polymorphisms.

OBJECTIVE

To determine the association of the vascular endothelial growth factor (VEGF) +936 C/T and +405 G/C, interleukine-6 (IL-6) -174 G/C, IL-1β-511 C/T, Apo A-1-75 G/A, Apo B-100 2488 C/T (Xbal) polymorphisms with preeclampsia in pregnant Peruvian women.

METHODS

Were included preeclamptic and healthy (control) pregnant women. Maternal blood samples were subjected to DNA extraction, and molecular genetic analysis was conducted using the PCR-RFLP technique and following a specific protocol for each gene. Allele and genotypic frequencies in the cases and controls were compared.

RESULTS

No association was found between the VEGF+936C/T and VEGF+405 polymorphisms and preeclampsia. The frequencies of the GG genotypes and the G allele of the -174 G/C polymorphism in the IL6 gene in preeclamptic and controls showed significant differences, with higher frequencies in cases. For the -511 C/T polymorphism of the IL-1β gene, no significant differences were found in the frequencies of TT genotypes compared with CT+CC. The genotypes and alleles of the Apo-A1-75 G/A and Apo-B100 Xbal variants showed no significant differences between cases and controls.

CONCLUSION

No association was found between the studied genetic markers and preeclampsia. However, in the -174G/C polymorphism of the IL-6 gene, significant differences were found mainly in the GG genotype and G allele.

The effects of high-density lipoprotein and oxidized high-density lipoprotein on forskolin-induced syncytialization of BeWo cells

INTRODUCTION

The negative relationship between maternal high-density lipoprotein-cholesterol (HDL-c) level during pregnancy and infant birth weight has been found. Syncytialization (differentiation and fusion) of trophoblast cells is important to fetal development. HDL has an antioxidant effect, and has been proved to protect trophoblast functions including hormone secretion and invasion. However, HDL is susceptible to oxidation, and high concentrations of HDL impair cell growth and oxidized HDL (oxHDL) inhibits cell proliferation and migration. Moreover, the effects of HDL and oxHDL on trophoblast syncytialization have not been characterized. The aim of this study was to investigate the effects of HDL and oxHDL on trophoblast syncytialization.

METHODS

Human choriocarcinoma trophoblasts (BeWo cells) were treated with human HDL or oxHDL and then induced to differentiate by forskolin in syncytialization assays. Expression levels of mRNAs and proteins regulating syncytialization were detected by real-time PCR and western blotting, respectively.

RESULTS

Treatments of HDL at high concentrations reduced human chorionic gonadotropin (hCG) secretion, placental alkaline phosphatase activity and fusion rates, and decreased the expressions of GCM1 and ERVW-1 mRNA as well as phospho-MAPK1/3 (p-MAPK1/3) and total MAPK1/3 protein in the forskolin-induced syncytialization of BeWo cells. Furthermore, treatment of oxHDL (20 μg/ml) decreased hCG secretion, but increased the expression of p-MAPK1/3 protein.

DISCUSSION

These data suggested that both HDL at high concentrations and oxHDL inhibited BeWo cells syncytialization, and might be harmful to placental and fetal development.

MiR-125b participates in the occurrence of preeclampsia by regulating the migration and invasion of extravillous trophoblastic cells through STAT3 signaling pathway

Preeclampsia (PE) is a major risk factor for maternal and fetal mortality. Studies showed that microRNAs (miRNAs) play important roles in PE, and are closely related to extra-villous trophoblastic proliferation and invasion. The current study determined miR-125b expression in PE patients, and explored the role of miR-125b in the occurrence and development of PE and its possible mechanism, aiming to provide a novel basis for the diagnosis and treatment of PE. The level of miR-125b in serum derived from pregnant women was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, invasion and migration of HTR-8/SVneo were determined by Cell Counting Kit-8 (CCK-8), Transwell and scratch assay, respectively. The target gene of miR-125b was predicted by Targetscan, and verified by luciferase reporter assay. The expressions of related proteins were determined by Western Blotting. The miR-125b level in the serum of PE patients was up-regulated as compared with normal pregnant women, and high level of miR-125b reduced cell proliferation, inhibited invasion and migration of HTR-8/SVneo as well as the expressions of STAT3, p-STAT3 and SOCS3, while low level of miR-125b produced the opposite results. STAT3 was predicted as the target gene of miR-125b, and the high level of miR-125b inhibited STAT3 signaling pathway. High expression of miR-125b may be involved in the occurrence of PE through inhibiting STAT3 pathway to inhibit the migration and invasion of extra-villous trophoblastic cells.

The Prion-like protein Shadoo is involved in mouse embryonic and mammary development and differentiation

Shadoo belongs to the prion protein family, an evolutionary conserved and extensively studied family due to the implication of PrP in Transmissible Spongiform Encephalopathies. However, the biological function of these genes remains poorly understood. While Sprn-knockdown experiments suggested an involvement of Shadoo during mouse embryonic development, Sprn-knockout experiments in 129Pas/C57BL/6J or 129Pas/FVB/NCr mice did not confirm it. In the present study, we analyzed the impact of Sprn gene invalidation in a pure FVB/NJ genetic background, using a zinc finger nuclease approach. The in-depth analysis of the derived knockout transgenic mice revealed a significant increase in embryonic lethality at early post-implantation stages, a growth retardation of young Sprn-knockout pups fed by wild type mice and a lactation defect of Sprn-knockout females. Histological and transcriptional analyses of knockout E7.5 embryos, E14.5 placentas and G7.5 mammary glands revealed specific roles of the Shadoo protein in mouse early embryogenesis, tissue development and differentiation with a potential antagonist action between PrP and Shadoo. This study thus highlights the entanglement between the proteins of the prion family.

Calcium deficient placental growth restriction is mediated by an increase in non-invasive integrin α5 and β4 phenotype

OBJECTIVES

Integrins are cell adhesion receptors that participated in endovascular invasion by cytotrophoblasts in preeclampsia. This study aimed to investigate the effect of calcium on cellular pathways influencing the trophoblast integration into endothelial cellular networks in vitro.

STUDY DESIGN

Red fluorescent-labelled human uterine myometrial microvascular endothelial cells (UtMVECs) were seeded on Matrigel. Green fluorescent-labelled HTR-8/SVneo trophoblast cells were then co-cultured with endothelial cells in different concentrations of calcium for 24 h.

MAIN OUTCOME MEASURES

The calcium effects on HTR-8/SVneo cell integration were quantified by Image J. Quantitative PCR was performed to measure mRNA expression of integrins α1, α5, α6, β1 and β4. The concentrations of interleukin IL-6, matrix metalloproteinase-2 (MMP-2), MMP-9, PlGF and sFlt-1 in the conditioned medium were measured by ELISA while levels of cytokines IL-1β, IL-8, IL-10, TNF-α and INF-γ were assessed by magnetic Luminex assays™.

RESULTS

Both calcium depletion (0.4 mM) and low calcium (1.8 mM) groups demonstrated inhibited integration of trophoblast cells into endothelial cellular networks, compared with the normal calcium group (2.4 mM). The IL-6 production was reduced from conditioned media in both calcium depletion and low calcium groups. In calcium depletion group, mRNA expression of integrin α5 and β4 in trophoblasts was increased while integrin α1 was decreased.

CONCLUSIONS

The in vitro trophoblast cell integration into endothelial cellular networks could be modified by altering media calcium through integrin switch away from integrins α5 and β4 and towards integrin α1 which may be required for healthy early trophoblast integration.

Role of LAMA4 Gene in Regulating Extravillous Trophoblasts in Pathogenesis of Preeclampsia

Background

Preeclampsia is a severe obstetric complication affecting the health of pregnant women. The aim of this study was to determine the effect of LAMA4 gene on extravillous trophoblasts (EVTs) in the pathogenesis of preeclampsia and its possible regulatory mechanism.

Material/Methods

HTR-8/SVneo cells were transfected with small-interfering ribonucleic acid (siRNA) targeting LAMA. The LAMA4 protein level was detected via Western blotting. Moreover, the influences of LAMA4 gene on the proliferation, migration and invasion of HTR-8/SVneo cells were detected via cell counting kit-8 (CCK-8) assay and Transwell assay. We also assessed the influences of LAMA4 gene on vascular endothelial growth factor (VEGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) messenger RNA (mRNA) levels in HTR-8/SVneo cells as measured by reverse transcription-polymerase chain reaction (RT-PCR).

Results

The cell lines with downregulation of LAMA4 gene were successfully established by transfection. Compared with those in the normal group, the proliferation, migration, and invasion of HTR-8/SVneo cells declined, the VEGF mRNA level was reduced, and the sFlt-1 mRNA level was increased in the silencing group.

Conclusions

Downregulation of the LAMA4 gene inhibits the proliferation, migration, and invasion of EVT to suppress the expression of vascular factors, leading to the occurrence or development of preeclampsia. Our data provide new insights into modulation of LAMA4 expression as a potential target for therapy against preeclampsia. Further research is needed on placenta sampling from pre-eclamptic pregnancies to validate the effect of LAMA4 expression compared to control pregnancies.

Effect of placental growth factor in models of experimental pre-eclampsia and trophoblast invasion

Placental growth factor (PlGF) is decreased in early gestation of pregnant women who subsequently develop pre-eclampsia. In this study, pre-emptive treatment with PlGF to prevent pre-eclampsia was evaluated in an in vivo rodent model of experimental pre-eclampsia (EPE) induced by TNF-α and in an in vitro model of human first-trimester trophoblast invasion. Pregnant C57/BL6 mice were treated with recombinant mouse placental growth factor-2 (rmPlGF-2) 100 μg/kg/day IP from gestational day (gd) 10. Animals had EPE induced by continuous TNF-α infusion on gd 13 and were subject to either continuous blood pressure monitoring by radiotelemetry throughout pregnancy or live placenta T₂ -weighted magnetic resonance imaging (MRI) to demonstrate placental function on gd 17. There was no difference in BP (P > .99), proteinuria (P = .9) or T₂ values on MRI (P = .9) between control and rmPlGF-2-treated animals. On gd 13, animals treated with rmPlGF-2 demonstrated increased placenta PlGF (P = .01) and Toll-like receptor-3 (P = .03) mRNA expression as compared with controls. Fluorescent-labelled human uterine microvascular endothelial cells and HTR8/SVNeo cells were co-cultured on Matrigel^™ and treated with recombinant human PlGF (rhPlGF) (10 ng/mL) and/or TNF-α (0.5 ng/mL). Trophoblast integration into endothelial networks was reduced by added TNF-α (P = .006), as was rhPlGF concentration in conditioned media (P < .0001). Cell integration was not ameliorated by addition of rhPlGF (P > .9). Although TNF-α-induced EPE was not reversed with pre-emptive rmPlGF-2, a further trial of pre-emptive rhPlGF in vivo is required to determine whether the absence of effect of rhPlGF demonstrated in vitro precludes PlGF as a preventative therapy for pre-eclampsia.

Preeclampsia: A review of the pathogenesis and possible management strategies based on its pathophysiological derangements

This review is divided into three parts. The first part briefly describes the pathogenesis of preeclampsia. This is followed by reviewing previously reported management strategies of the disease based on its pathophysiological derangements. Finally, the author defines the safe and acceptable methods/medications that may be used to 'prevent' preeclampsia (in high risk patients) and those that may be used to 'treat' preeclampsia (meant to prolong the pregnancy in patients with established preeclampsia). The review concludes that multi-center trials are required to include multiple drugs in the same management protocol.

Oxidative modifications of foetal LDL-c and HDL-c lipoproteins in preeclampsia

Background

Oxidative modifications have been observed in lipids and proteins in lipoproteins isolated from women with preeclampsia. Thus, newborns could also be susceptible to this damage directly through their mothers. In this study, we evaluated the oxidative profile of LDL-c and HDL-c lipoproteins isolated from the umbilical cord from newborns born to women with preeclampsia.

Methods

Thirty newborns born to women with preeclampsia and thirty newborns born to women with healthy pregnancies were included. Lipid-damage biomarkers, including conjugated dienes, lipohydroperoxides and malondialdehyde, were measured. The reduction of nitroblue tetrazolium, formation of dityrosines, and carbonylation of proteins were assessed as indicators of protein damage. The protective activity of paraoxonase-I on HDL-c particles was evaluated. The total antioxidant capacity and lipid profiles were quantified in plasma. Data were analysed using Student’s t-tests and Pearson correlation coefficients.

Results

Compared with the control group, the preeclampsia group had an increase in the percentage of lipid damage in both lipoproteins. There was an increase of 23.3 and 19.9% for conjugated dienes, 82.4 and 21.1% for lipohydroperoxides, and 103.8 and 51.5% for malondialdehyde in LDL-c and HDL-c, respectively. However, these infants did not show evident damage in protein oxidation. The activity of the enzyme paraoxonase-I was decreased by 36.2%; by contrast, the total antioxidant capacity was increased by 40% (protein) and 28.8% (non-protein).

Conclusions

The oxidative modifications that occur in HDL-c and LDL-c isolated from newborns from women with preeclampsia are mainly caused by lipoperoxidation processes related to evident paraoxonase-I inactivation. The absence of protein damage is likely linked to an increase in total antioxidant capacity. Therefore, antioxidant support could be helpful in reducing oxidative stress in mother/newborn dyads.