Expression of Human Leukocyte Antigen-G during Normal Placentation and in Preeclamptic Pregnancies

Objectives. This study was undertaken to investigate the expression pattern of human leukocyte antigen-G (HLA-G) during normal placentation and determine whether altered expression of HLA-G is associated with severe preeclampsia. Methods. We investigated HLA-G protein levels in first (n = 27), second (n = 7), and third trimester placentas (n = 10) from normal pregnancies, and determined HLA-G levels in term placentas from normal (n = 15) and severe preeclamptic pregnancies (n = 14) using real-time RT-PCR and western blot analysis. Results. In normal placentas, HLA-G protein expression reached a peak level at gestational weeks 6 and 7, then gradually decreased from week 8 to third trimester (p < 0.05). In preeclamptic placentas, both HLA-G mRNA and protein levels were decreased significantly in comparison with normal term placentas (p < 0.05). Conclusion. HLA-G may contribute to placentation during early and mid-term pregnancy, and participate in maintaining gestation during term pregnancy. The reduced level of HLA-G may be associated with pathogenesis of preeclampsia.     

Autophagy protects against oxidized low density lipoprotein-mediated inflammation associated with preeclampsia

IntroductionInflammatory responses play an important role in the pathogenesis of preeclampsia. Recently, the anti-inflammatory role played by autophagy has drawn increasing attention. Our aim was to investigate variations in autophagy in preeclampsia and protection against oxidized low-density lipoprotein (oxLDL)-mediated inflammation by autophagy.MethodsWe used immunohistochemistry, immunofluorescence, quantitative real-time PCR, and western blotting to analyze the expression of autophagy proteins (beclin-1 and LC3II/LC3I) in preeclampsia placentas and in JEG-3 cells treated with oxLDL and rapamycin.ResultsWe found a decreased level of autophagy proteins in preeclampsia placentas, and oxLDL did not induce autophagy in JEG-3 cells. Furthermore, when cells were pretreated with rapamycin, autophagy was activated and expression of inflammatory factors (tumor necrosis factor-α and interleukin-6) induced by oxLDL was downregulated.ConclusionWe conclude that impaired autophagy in preeclampsia has potential to decrease trophoblast protection from oxidative and inflammatory stress, thereby contributing to the pathogenesis of preeclampsia.     

Expression of low density lipoprotein receptor messenger ribonucleic acid in placentas from pregnancies with intrauterine growth retardation.

The low density lipoprotein receptor plays an important role in the uptake of maternal plasma lipoproteins for placental steroid metabolism. Using an RNase protection assay, the expression of low density lipoprotein receptor mRNA was measured in human placentas from pregnancies in the second and third trimester and from pregnancies with intrauterine growth retardation. Pregnancies complicated by intrauterine growth retardation showed a significantly higher expression (1.28), compared with the term and preterm pregnancies (P < 0.05). The increased low density lipoprotein receptor expression in placentas from pregnancies with intrauterine growth retardation could be a compensatory mechanism for the lower circulating low density lipoprotein concentrations in women with intrauterine growth retardation.     

Downregulated N-acetylglucosaminyltransferase III is involved in attenuating trophoblast migration and invasion under hypoxia–reoxygenation condition

Objective: Many studies have confirmed that N-acetylglucosaminyltransferase III (GnT-III) is correlated with tumor invasion and metastasis. However, the expression of GnT-III and its role in normal pregnancy and preeclampsia (PE) has not been reached. So the primary objective of this study is to determine GnT-III expression in normal pregnancy and whether its expression is vulnerable to oxidative stress in the trophoblast cells.

Methods: Human first trimester villous tissues from normal pregnancies and third trimester placentas from pregnancies with or without preeclampsia (PE) were used for the detection of GnT-III expression. Human first trimester extravillous trophoblast cell line (HTR8/SVneo) exposed to hypoxia/reoxygenation (H/R) condition was employed as an oxidative stress model in vitro to investigate the expression of GnT-III.

Results: GnT-III was strongly expressed in cytotrophoblast (CTBs), syncytiotrophoblast (STBs) and the trophoblast columns (TCs) of human placental villi, and decidual cells in the maternal decidua. The expression of GnT-III was decreased in PE placentas compared with the normal control placentas. In addition, GnT-III was found to have decreased expression in H/R-exposed HTR8/SVneo cells, and the invasive and migratory abilities of HTR8/SVneo cells were attenuated, too.

Conclusions: These findings suggest that GnT-III is an important regulator at the maternal-fetal interface during early pregnancy. Excessive oxidative stress can decrease GnT-III expression in trophoblast and the decreased expression of GnT-III may be involved in the development of preeclampsia.     

Expression of low density lipoprotein receptor messenger ribonuclein acid in placentas from pregnancies with preterm delivery and pregnancies with intrauterine growth retardation

The low density lipoprotein receptor plays an important role in the uptake of maternal plasma lipoproteins for placental steroid metabolism. Using an RNase protection assay, the expression of low density lipoprotein receptor mRNA was measured in human placentas from pregnancies in the second and third trimester and from pregnancies with intrauterine growth retardation. Pregnancies complicated by intrauterine growth retardation showed a significantly higher expression (1–28), compared with the term and preterm pregnancies (   P < 0.05  ). The increased low density lipoprotein receptor expression in placentas from pregnancies with intrauterine growth retardation could be a compensatory mechanism for the lower circulating low density lipoprotein concentrations in women with intrauterine growth retardation.     

Paraoxonase gene polymorphism, serum lipid, and oxidized low-density lipoprotein in preeclampsia

OBJECTIVES: Human paraoxonase-1 (PON-1) is thought to play a role in preeclampsia and atherosclerosis, mainly through a reduction in low-density lipoprotein oxidation. Oxidized low-density lipoprotein (LDL) is very important in endothelial dysfunction of preeclampsia. The aim of the present study was to investigate the association between PON1 gene polymorphism and preeclampsia and to determine concentrations of serum lipid in preeclampsia patients. We aimed also to evaluate serum oxidized LDL levels in normal and preeclampsia patients. STUDY DESIGN: We performed the present study in 57 control women and 32 preeclampsia patients. PON-1 genotypes were determined by polymerase chain reaction amplification and restriction fragment length polymorphism. Serum triglyceride, cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol levels were measured. We also measured serum levels of oxidized LDL by ELISA method. RESULTS: There was no significant difference in PON1 genotype frequencies between the control and preeclampsia patients. The levels of serum cholesterol and high-density lipoprotein were significantly lower in preeclampsia patients compared with that of the control women (p=0.05, and p<0.01, respectively). The serum levels of oxidized LDL in preeclampsia patients were significantly higher than those in the control women (p=0.001). CONCLUSIONS: These findings support the importance of the atherogenic lipid profile and oxidized LDL that is enhanced in preeclampsia, and these findings may be significant contributors to endothelial dysfunction.     

Regional variations in contractile responses to prostaglandins and prostanoid receptor messenger ribonucleic acid in pregnant baboon uterus

Objectives: The aims of this study were to compare (1) the contractile responses of the lower uterine segment and fundus to prostaglandins, (2) expression of genes encoding prostanoid receptors in myo-metrium from different regions of the uterus, and (3) the distribution of expression of genes encoding prostanoid receptors (P receptors) in key intrauterine tissues. Study Design: Cesarean hysterectomy was performed in 8 pregnant baboons, not in labor, in the last third of pregnancy. Contractile responses of fresh tissue were quantified in a superfusion system. Polyadenylated ribonucleic acid was extracted from frozen tissue and gene expression was quantified by Northern blot analysis with complementary deoxyribonucleic acid probes. Results: Prostaglandin E₂ contracted strips of myometrium from the fundus but had no significant effect on strips from lower uterine segment. Prostaglandin F_2α contracted myometrium from both regions equally. Compared with fundus tissue, lower uterine segment tissue had greater expression of EP₂ receptor messenger ribonucleic acid, less expression of EP₃ receptor messenger ribonucleic acid, but similar levels of EP₄ receptor and FP receptor messenger ribonucleic acid. EP₂ receptor, EP₃receptor, and EP₄ receptor messenger ribonucleic acids were also detected in cervix, decidua, and chorion. EP₂ receptor messenger ribonucleic acid was most abundant in the cervix, EP₃ receptor messenger ribonucleic acid was most abundant in the myometrium, and EP₄ receptor messenger ribonucleic acid was most abundant in the decidua. Conclusions: The reduced contractile response of lower uterine segment tissue to prostaglandin E₂ is paralleled by greater inhibitory EP₂ receptor expression and less contractile EP₃ receptor expression, a pattern similar to that seen in the cervix. Drugs with selective activity at prostanoid receptor types and subtypes are likely to allow safer and more effective control of the uterus and cervix than native prostaglandins. (Am J Obstet Gynecol 1998;179:1545-52.)     

Expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) in human preeclamptic placenta: possible implications in the process of trophoblast apoptosis

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) was originally identified as a receptor for oxidatively modified low-density lipoprotein. It has been reported that oxidative stress and hyperlipidemia play important roles in the etiology of preeclampsia, and that placental oxidative stress may stimulate syncytiotrophoblast apoptosis in preeclampsia. In this study, we examined the expression of LOX-1 in the human placentas of normal pregnancies and in preeclampsia using immunohistochemistry and Western blot analysis, and proposed that LOX-1 has a role in trophoblast apoptosis. To analyze apoptotic activity, the expression of the specific caspase cleavage site within cytokeratin 18 was assessed immunohistochemically using the monoclonal antibody M30 CytoDeath. Both LOX-1 and M30 immunoreactivity occurred predominantly in syncytiotrophoblasts. A significantly higher number of LOX-1 and M30-positive cells were found in preeclamptic placentas than in normal placentas. The number of M30-positive cells correlated with the apoptotic index of trophoblasts determined by TdT-mediated dUTP nick-end labeling (TUNEL). Syncytiotrophoblasts showing apoptotic activity were immunopositive to LOX-1 by double immunohistochemical fluorescence. We suggest that the functional role of syncytiotrophoblasts in placental dysfunction results from the localization and upregulation of LOX-1 in the preeclamptic placenta, possible implications in upregulation of syncytiotrophoblast apoptotic activity in preeclampsia.     

Increased placental apoptosis in intrauterine growth restriction

OBJECTIVES: Our purpose was to investigate a possible role for apoptosis in the pathophysiologic mechanisms of intrauterine growth restriction. STUDY DESIGN: Placental samples were obtained from 43 uncomplicated third-trimester pregnancies and from 26 pregnancies complicated by intrauterine growth restriction. The definition used to identify cases of intrauterine growth restriction depended on three criteria: clinical evidence of suboptimal growth, ultrasonographic evidence of deviation from an appropriate growth percentile, and individualized birth weight ratios <10th percentile. Light microscopy was used to quantify the incidence of apoptosis. Electron microscopy and TUNEL (terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick end labeling) staining were used to confirm the occurrence of apoptosis. RESULTS: Quantification of apoptosis (medians and interquartile ranges) resulted in the following values: normal third trimester (n = 43) 0.14% of cells (0.08% to 0.20%) and intrauterine growth restriction third trimester (n  = 26) 0.24% of cells (0.16% to 0.29%). The incidence of apoptosis was significantly higher in placentas from pregnancies with intrauterine growth restriction compared with normal third-trimester placentas (p < 0.01, Mann Whitney U test). CONCLUSIONS: These results suggest that apoptosis may play a role in the pathophysiologic mechanisms of intrauterine growth restriction.(Am J Obstet Gynecol 1997;177:401)     

Receptor expression by JEG-3 trophoblast cells in the presence of placenta secreted factors

Abstract

Preeclampsia still remains one of the most severe pregnancy complications and is an actual problem in the obstetrics practice. At present, the joint impact of cytokines and other placenta secreted factors on trophoblast cell functional activity during preeclampsia complicated pregnancy remains unclear. The aim of the study is to estimate the surface receptors expression by trophoblast cells in the presence of placenta secreted factors during physiological pregnancy and at preeclampsia. Trophoblast cells of the JEG-3?line were incubated in the presence of supernatants obtained by cultivation of placentas from women with physiological pregnancy and with preeclampsia. Surface receptors expression by trophoblast cells was estimated by FACS Canto II flow cytometer. It was established that in the third trimester both under normal and pathological conditions, the placenta secreted factors impact on the cytokine receptor expression by trophoblast differs while the trophoblast response capacity to the migration and proliferation stimulating and inhibiting signals remains stable. JEG-3?line cells enhanced the expression of CD186, CD140a, Integrin β6, VE-cadherin, CD29, and CD140a in the case of incubation in the presence of placenta supernatants from the third-trimester pregnancy complicated with preeclampsia compared to incubation in the presence of placenta supernatants form the third trimester of physiological pregnancy.     

Prostaglandin endoperoxide H synthase type 1 and type 2 messenger ribonucleic acid in human fetal tissues throughout gestation and in the newborn infant

OBJECTIVE: We determined the relative abundance of prostaglandin endoperoxide H synthase type 1 and type 2 messenger ribonucleic acid levels in the human fetus and newborn infant. STUDY DESIGN: We used ribonuclease protection assays and normalized values to messenger ribonucleic acid of cyclophilin. Tissues were obtained from all 3 trimesters and in the first 9 days of the newborn period. RESULTS: Prostaglandin endoperoxide H synthase type 1 and type 2 messenger ribonucleic acid is present in every fetal tissue examined (lung, kidney, intestine, heart, brain, and stomach). Kidney and lung demonstrated no changes in the expression of prostaglandin endoperoxide H synthase type 1 messenger ribonucleic acid with gestational age, whereas postnatal levels in lung were one third those in the first trimester (P <.05). A large increase (5-fold to 30-fold; P <.05) occurred throughout gestation for the expression of prostaglandin endoperoxide H synthase type 2 messenger ribonucleic acid in intestine, lung, and kidney, which extended into the newborn period for lung and kidney. CONCLUSIONS: These data imply that the expression of prostaglandin endoperoxide H synthase type 2 messenger ribonucleic acid may be responsible for prostaglandin-related effects and is coordinated in several human fetal tissues in late gestation.     

The Expression of Connective Tissue Growth Factor in Pregnancies Complicated by Severe Preeclampsia or Fetal Growth Restriction

We tested the hypothesis that the expression of placental connective tissue growth factor (CTGF) is enhanced in pregnancies complicated by severe preeclampsia (PE) or fetal growth restriction (FGR). CTGF expression was analyzed using immunostaining, western blot and real-time quantitative PCR in placental samples obtained after third trimester cesarean deliveries without labor from women with severe PE (n = 11), idiopathic FGR (n = 14), or healthy controls (n = 14). Serum CTGF concentrations were analyzed using ELISA. We found that CTGF was stably expressed in villous trophoblasts throughout pregnancy. The expression of CTGF mRNA in placentas from severe PE or FGR was higher than placentas from controls. Whereas the levels of placental CTGF protein were similar between normal and severe PE, maternal and fetal serum CTGF levels were elevated in severe PE. Maternal CTGF levels were also distinctively elevated in women with PE or FGR with histological evidence of placental injury. The enhancement of CTGF expression as well as serum CTGF levels in clinical conditions attributed to placental dysfunction suggests a role for this secretary protein in the pathophysiology of placental injury or its sequelae.     

Preeclampsia associates with RECK-dependent decrease in human trophoblasts migration and invasion

IntroductionPreeclampsia is characterized by reduced invasion capacity of trophoblasts involving lower matrix metalloproteinase (MMP) activity. Cell invasion is reduced by reversion-inducing-cysteine-rich protein with Kazal motifs (RECK), a plasma membrane protein that inhibits MMP in several cell types. However, it is unknown whether this mechanism happens in the human placenta from preeclampsia. The hypothesis of this study sustains that RECK expression is increased leading to reduced trophoblasts invasion in preeclampsia.MethodsRECK expression in the human first trimester trophoblast cell line HTR8/SvNeo and in placentas from normal (n = 4) and preeclampsia (n = 4) pregnancies was evaluated by Western blot and immunofluorescence. MMP-dependent gelatin hydrolyzation was measured by in situ zymography and gelatinase assay in placental and cell extracts. RECK was overexpressed (plasmidial vector transfection) or partially reduced (shRNA) to evaluate its role in HTR8/SVneo cell migration and invasion.ResultsRECK was expressed in trophoblasts layer in human placentas. Preeclampsia resulted in higher placental RECK protein abundance, reduced MMP function, and higher level of fibronectin (a MMP substrate) compared with placentas from normal pregnancies. RECK is also expressed in HTR-8/SVneo cells. Reduced RECK expression resulted in higher MMP-dependent gelatin hydrolyzation, associated to higher migration and invasion of HTR8/SVneo cells. However, RECK overexpression associated with reduced hydrolyzation, cell migration and invasion.DiscussionRECK is overexpressed in human trophoblasts from preeclampsia and may be responsible of this disease-associated lower migration and invasion of this cell type.     

External iliac artery Doppler assessment in the prediction of adverse pregnancy outcomes

Purpose: The purpose of this study is to investigate the potential role of the mean external iliac artery pulsatility index (EIA-PI) as a predictor of adverse obstetric outcomes such as preeclampsia, gestational hypertension and small for gestational age (SGA).

Methods: In women attending for first trimester screening at 11?+?0–13?+?6 weeks of gestation, we recorded maternal characteristics and measured EIA mean PI and uterine artery mean PI. We compared EIA mean PI in those that developed preeclampsia (n?=?84), gestational hypertension (n?=?50) or small for gestational age (n?=?444) with those unaffected (n?=?3736). Regression analysis was used to first determine which of the factors among the maternal variables were significant predictors of EIA mean PI in the unaffected group and, second, to predict adverse pregnancy outcomes.

Results: In the unaffected group, EIA mean PI increased with maternal age and decreased with mean blood pressure. Additionally, EIA mean PI was lower in cigarette smokers. Compared with the unaffected group, EIA mean PI was significantly lower in women who develop gestational hypertension or SGA below third centile.

Conclusion: EIA mean PI in the first trimester is decreased in women who develop gestational hypertension and in those complicated by SGA below third centile. More studies are needed to confirm these findings.     

Preeclampsia is associated with an elevation of plasma sMet concentrations in the second trimester

Abstract

Objective: The aim of this study was to investigate the association between anti-angiogenic factor soluble c-Met (sMet) concentrations in maternal plasma and the risk of preeclampsia.

Methods: The pregnant women included in this study (1) had subsequent preeclampsia (n?=?52) and were compared to normal controls (n?=?104) at the time of amniocentesis (15–20 weeks); and (2) had preeclampsia (n?=?63) and were compared to normal controls (n?=?112) at the time of diagnosis of preeclampsia (29–40 weeks). sMet concentrations were measured by ELISA. Non-parametric statistics were used for analysis.

Results: Maternal plasma sMet concentrations were significantly higher in both women with subsequent preeclampsia (median: 1372.7?ng/ml versus 1100.5?ng/ml; p?=?0.036) and women with preeclampsia (median: 1651.9?ng/ml versus 1364.7?ng/ml; p?<?0.001) than in the controls. After adjusting for potential confounding factors, the risks of developing preeclampsia were as follows: adjusted odds ratio 2.5 (95% confidence interval, 1.2–5.2; p?=?0.016) for second trimester sMet concentration with a cut-off value of 1223.5?ng/ml and 4.4 (95% confidence interval, 2.2–9.1; p?<?0.001) for third trimester sMet concentration with a cut-off value of 1460.3?ng/ml.

Conclusion: Elevated maternal plasma sMet concentrations were independently associated with the increased risk of preeclampsia.     

Low plasma levels of decoy receptor 3 (DcR3) in the third trimester of pregnancy with preeclampsia

ObjectiveThe pathophysiology of preeclampsia, a major threat during pregnancy characterized by excessive inflammatory status, remains unclear. Decoy receptor 3 (DcR3), a soluble member of the tumor necrosis factor receptor (TNFR) superfamily, is capable of inducing anti-apoptosis via binding with TL1A and anti-inflammation by driving Th2 immune reactions. DcR3 may, therefore, play a role in immune modulation during pregnancy. The purpose of this study is to explore the role of DcR3 in normal and preeclamptic pregnancies.Materials and methodsPlasma samples from 104 normal pregnant women (26, 42, and 36 in the first, second, and third trimester, respectively) and 10 patients with preeclampsia in the third trimester were collected. Plasma DcR3 levels were determined by using commercial ELISA kits. ANOVA and linear regression analysis were performed to analyze the relationship between gestational age and DcR3 levels. After adjusting for gestational days, the levels of plasma DcR3 in preeclamptic and non-preeclamptic women in the third trimester were compared.ResultsThe plasma levels of DcR3 gradually decreased as the gestational days increased during pregnancy (p < 0.05). In the third trimester, pregnant women with preeclampsia had significantly lower plasma DcR3 levels compared to non-preeclamptic women (p < 0.05).ConclusionsWe found that plasma DcR3 levels gradually decreased as gestation progressed. The levels of plasma DcR3 in preeclamptic women were significantly lower than those of normal pregnant women, suggesting that a potential involvement of DcR3 in normal pregnancy and decreased levels of DcR3 may be related to preeclampsia.