Serum leptin levels in preeclamptic pregnant women: relationship to thyroid-stimulating hormone, body mass index, and proteinuria

The objective of this study was to evaluate the change in maternal serum leptin levels in preeclampsia and to study the relationship between maternal serum leptin and thyroid-stimulating hormone (TSH), body mass index (BMI), newborn weight, and proteinuria. Eighty-five pregnant women were included in this prospective study, of whom 50 were preeclamptic and 35 were normotensive. Maternal serum leptin levels were measured by the radioimmunoassay technique and TSH levels were measured by the electrochemiluminescence immunoassay method. The maternal serum leptin levels of preeclamptic and normotensive pregnant women were compared. In each group, the relationship between maternal serum leptin levels and TSH levels, BMI, newborn weight, and proteinuria was evaluated. The maternal serum leptin level was significantly higher in the preeclamptics than in the normotensive pregnant women. In the preeclamptic group, there was a strong positive correlation between maternal serum leptin levels and BMI (r =- 0.80; p < 0.001), a very weak positive correlation between maternal serum leptin levels and proteinuria (r = 0.305; p < 0.05), and a very weak inverse correlation between maternal serum leptin levels and birth weight (r = -0.377; p < 0.01). In the same group, there was no correlation between maternal serum leptin and serum TSH levels (r = 0.22; p > 0.05; Pearson correlation test). Leptin may be involved in the pathology of preeclampsia, and elevated maternal serum leptin levels may be a marker for the early stages of preeclampsia in pregnant women.     

Trophoblast debris extruded from preeclamptic placentae activates endothelial cells: A mechanism by which the placenta communicates with the maternal endothelium

Introduction

Preeclampsia is characterized by maternal endothelial dysfunction. While the mechanisms leading to preeclampsia are unclear, a factor(s) from the placenta is responsible for triggering the disease. One placental factor implicated in triggering preeclampsia is trophoblast debris which may transmit pathogenic signals from the placenta to endothelial cells. In this study, we investigated whether trophoblast debris from preeclamptic placentae triggered endothelial cell activation.

Methods

Trophoblast debris from preeclamptic or normotensive placentae, or trophoblast debris from normal placental explants that had been cultured with preeclamptic (n = 14) or normotensive sera (n = 14) was exposed to endothelial cells. Activation of the endothelial cells was quantified by cell surface ICAM-1 and U937 adhesion to endothelial cells. The levels of IL-1β, pro-caspase-1 and active caspase-1 in the trophoblast debris were measured.

Results

Compared to controls, the levels of ICAM-1 and U937 adhesion to endothelial cells were significantly increased following exposure of the endothelial cells to trophoblast debris from preeclamptic placentae or placentae treated with preeclamptic sera. The levels IL-1β, pro-caspase-1 and active caspase-1 were significantly increased in both trophoblast debris from preeclamptic placentae and placentae treated with preeclamptic sera.

Discussion

These results provide the first direct evidence that trophoblast debris produced from preeclamptic placentae or placentae treated with preeclamptic sera can activate the endothelium.

Conclusions

Trophoblast debris from preeclamptic but not normotensive placentae can induce endothelial cell activation. This may be one mechanism by which the preeclamptic placenta communicates with the maternal endothelium to induce activation of the endothelium.     

Amniotic fluid and maternal serum leptin levels in pregnant women who subsequently develop preeclampsia

OBJECTIVES: To study the correlation between amniotic fluid leptin levels and maternal serum leptin levels during the early second trimester, and to determine whether the ratios of amniotic fluid leptin levels to maternal serum leptin levels are elevated in pregnant women who subsequently develop preeclampsia. STUDY DESIGN: Samples from 120 pregnant women were included in this prospective study, of which 20 were from pregnant women who subsequently developed preeclampsia and 100 were from normal pregnant women. Both the amniotic fluid and the maternal serum leptin levels were ascertained by radioimmunoassay (RIA). RESULTS: A strong correlation between amniotic fluid leptin levels and maternal serum leptin levels was observed in both preeclamptic and normal pregnant women. In addition, the ratios of amniotic fluid leptin levels to maternal serum leptin levels were positively correlated to amniotic fluid leptin levels, but negatively correlated to maternal serum leptin levels. Furthermore, the ratios of amniotic fluid leptin levels to maternal serum leptin levels in preeclamptic women were significantly higher than those in normal pregnant women. CONCLUSIONS: Amniotic fluid leptin levels correlated with maternal serum leptin levels during the early second trimester. The ratios of amniotic fluid leptin levels to maternal serum leptin levels were elevated in preeclamptic women. However, the maternal serum leptin levels themselves showed no such elevation. Therefore, this elevated ratio may be a marker at the early stage of pregnancy in preeclamptic women.     

Elevated amniotic fluid leptin levels in pregnant women who are destined to develop preeclampsia

OBJECTIVE: To analyze whether leptin levels of the amniotic fluid elevate during early pregnancy in women destined to develop preeclampsia and to evaluate the relationship between amniotic fluid leptin levels and gestational age, maternal body mass index, and fetal sex. STUDY DESIGN: Leptin levels of the amniotic fluid were compared in two groups of women, preeclamptic (n = 20) and normotensive pregnant (n = 40), matched for fetal sex, maternal body mass index at sampling, gravidity and fetal gestational age at sampling. Furthermore, amniotic leptin levels in 400 normotensive pregnant women were analyzed for their correlation with gestational age, maternal body mass index, and fetal sex. RESULTS: Median leptin concentrations were significantly higher (p < 0.001) in the women with preeclampsia (7.3+/-0.7 ng/ml) than in the normotensive pregnant women (4.1 +/- 0.3 ng/ml), independent of fetal sex. The leptin levels in the amniotic fluid decreased with advanced gestational age (r = 0.24, p < 0.001). Amniotic fluid leptin levels in the pregnant women carrying a female fetus (5.6+/-0.3ng/ml) were significantly higher than those carrying a male fetus (4.7+/-0.2 ng/ml) (p = 0.004). CONCLUSION: Higher amniotic fluid leptin levels were observed in the preeclamptic pregnant women, and they decreased as gestational age advanced. Furthermore, the women with a female fetus were noted to have higher amniotic fluid leptin levels.     

A comparative study of serum soluble vascular cell adhesion molecule-1 and soluble intercellular adhesion molecule-1 in preeclampsia.

OBJECTIVES: Maternal serum soluble vascular cell adhesion molecule-1 (sVCAM-1) and soluble intercellular adhesion molecule-1 (sICAM-1) were evaluated in preeclampsia to investigate whether these molecules could be helpful with regard to this pregnancy complication. STUDY DESIGN: The study population was composed of 30 preeclamptic patients with a mean gestational age of 35.5 +/- 4.6 weeks and 20 age-matched and gestational age-matched normotensive uncomplicated pregnancies (controls). Blood samples from 7 of the 30 preeclamptic patients and 15 of the 20 controls in the second trimester were also analyzed. Data were analyzed by parametric methods. RESULTS: Significantly higher maternal serum sVCAM-1 levels were found in both groups of preeclamptic patients with and without fetal growth restriction (981 +/- 145 ng/ml; n = 13; p < 0.0005 and 846 +/- 84 ng/ml; p < 0.02, respectively) compared with controls (668 +/- 186 ng/ml). In contrast, no significant difference was found in maternal serum sICAM-1 levels between preeclamptic and normotensive pregnancies, or in both adhesion molecules (1) in the controls between second and third trimester samples and (2) in the second trimester between pregnant women who developed preeclampsia later and gestational age-matched controls. CONCLUSION: These findings show a selective significant elevation of maternal serum sVCAM-1 in preeclampsia, with the highest values in cases complicated with fetal growth restriction, perhaps reflecting its angiogenic function. Hence, sVCAM-1 could be helpful in the diagnosis of this fetal complication in preeclampsia.     

Plasma IL-4, IL-8, IL-12, interferon-γ and CRP levels in pregnant women with preeclampsia,and their relation with severity of disease and fetal birth weight

Objective: The aim of the present study was to evaluate the hypothesis that preeclampsia is associated with increased systemic inflammatory responses of Th1-type as well as decreased Th2-type responses compared with normal pregnancy. We also sought to determine whether there was a correlation between these markers with severity of preeclampsia and fetal birth weight. Methods: The study population consisted of maternal age, gestational age, and body mass index matched 138 pregnant women; 56 normotensive healthy pregnant women (group 1), 42 women with mild preeclampsia (group 2), 40 women with severe preeclampsia (group 3). Results: Plasma interleukin (IL)-8 and C-reactive protein (CRP) levels were significantly higher in group 3 than group 1 (p?<?0.05). Plasma IL-4, IL-12, and interferon (IFN)-γ levels were similar in all groups. Although plasma IL-8 and CRP levels of mild preeclamptic group were higher than control group and lower than severe preeclamptic group, the differences were not statistically significant. There was a positive correlation between IL-12 and fetal birth weight in severe preeclamptic group (p?<?0.05). Conclusions: Elevated maternal serum pro-inflammatory cytokine IL-8 and CRP in severe preeclamptic women compared with normal pregnant women supports the hypothesis that preeclampsia is associated with increased inflammatory responses.     

Cerebro vascular reactivity (CVR) of middle cerebral artery in response to CO25% inhalation in preeclamptic women

Abstract

Objective: To compare the cerebro vascular reactivity (CVR) of middle cerebral artery (MCA) in response to CO2_5% inhalation between preeclamptic and normotensive pregnant women, also, between mild and severe preeclampsia.

Study design: A comparative study was performed on 61 women with preeclampsia and 65 normotensive pregnant women who were in the third trimester of gestation. MCA transcranial Doppler ultrasound was used to measure CVR in response to CO2_5% inhalation. Pulsatility index (PI), resistance index (RI), blood pressure, maternal age, gestational age and gravidity were also recorded.

Results: Baseline PI and RI were lower in the preeclamptic group (p?<?0.05). Inhalation of CO2_5% caused significant increase in CVR among normotensive pregnant women in comparison with preeclamptic group (1.006?±?0.229 versus 0.503?±?0.209, p?=?0.0001). Significantly, more cerebral vasodilatation was found among mild preeclamptic women in comparison with severe preeclamptic women (0.583?±?0.193 versus 0.383?±?0.173, p?=?0.0001). The receiver operating characteristics curve analysis revealed acceptable difference between CO2 stimulation test of preeclamptic and normotensive women (Area under curve?=?0.973, p?=?0.0001).

Conclusion: CVR in response to CO2_5% is less in preeclamptic pregnant women than normotensives, also, in severe preeclampsia, it is less than mild preeclampsia.     

The severity of hypoxic changes and oxidative DNA damage in the placenta of early-onset preeclamptic women and fetal growth restriction

Objective: To investigate the relation between the severity of hypoxic changes and oxidative DNA damage in the placenta of early and late-onset preeclampic women and fetal growth restriction (FGR), serum parameters of oxidative stress, placental hypoxic change, and oxidative DNA damage were determined. Methods: We examined 10 participants with uncomplicated pregnancies, 13 with early-onset and 12 with late-onset preeclampsia. Maternal and umbilical plasma derivatives of reactive oxygen metabolites (d-ROMs) were measured as markers of oxygen free radicals. Immunohistochemical analysis was performed to measure the proportion of placental trophoblast cell nuclei staining positive for 8-hydroxy-2’-deoxyguanosine (8-OHdG), redox factor-1 (ref-1), and hypoxia-induced factor-1α (HIF-1α), which are markers of oxidative DNA damage, repair functions, and hypoxia status, respectively. Results: 8-OHdG was higher in both preeclamptic groups, but significantly higher in the early-onset preeclamptic group. Ref-1 was higher in the late-onset preeclamptic group. HIF-1α was higher in both preeclamptic groups, with a tendency towards a higher in the early-onset preeclamptic group. Conclusions: Our findings indicate that the severity of hypoxic changes and oxidative DNA damage are greater in the placenta of women with early-onset preeclampsia, and that the prolonged preeclamptic conditions may reduce placental blood flow, ultimately leading to FGR.     

Correlation between maternal first trimester plasma leptin levels and birth weight among normotensive and preeclamptic women

Objective.?To determine the connection between maternal first trimester serum leptin levels and newborn weight.

Methods.?The study included 37 preeclamptic women and 53 normotensive women who considered the control group. Maternal blood samples were withdrawn at 13 weeks of gestation for the measurement of leptin concentrations. Birth weights were transformed to z-scores according to maternal and obstetrical features, based on customised centiles. Non-parametric tests, student's t-test, Pearson's correlation, Spearman's correlation and linear regression analysis were performed in our analysis.

Results.?Pre-pregnancy body mass index and first trimester maternal plasma leptin levels were significantly higher among women with preeclampsia (p?=?0.015 and p?<?0.001, respectively). Birth weight z-score was negatively correlated with leptin levels (r?=??0.570, p?<?0.001), in preeclamptic group and in control group (r?=??0.477, p?<?0.001). The regression modelling demonstrated a significant negative association between birth weight z-scores and leptin for both groups.

Conclusion.?Maternal first trimester serum leptin demonstrates a significant negative association with neonatal weight in preeclamptic pregnancies and to a lesser extent in normotensive pregnancies. A possible leptin's involvement in pathophysiological adaptations that define the foetal growth potential can be supported.     

Comparison of interleukin-6 levels in maternal and umbilical cord blood in early- and late-onset preeclampsia

Purpose: Increased inflammatory response and cytokines are claimed to play a significant role in the etiology of preeclampsia. Interleukin-6 (IL-6) is a proinflammatory cytokine. Limited number of studies evaluating IL-6 levels in preeclamptic patients have produced conflicting results. Therefore, the present study sought to compare maternal and umbilical cord serum levels of IL-6 in early- and late-onset preeclamptic pregnancies as well as in normal pregnancies. Materials and methods: A total of 69 participants were enrolled in the study. The control group consisted of 24 participants with normal pregnancies. Preeclampsia group consisted of 45 participants. The preeclampsia group was further classified into the subgroups of early- and late-onset preeclampsia. Late-onset preeclampsia group consisted of 24 women whereas early-onset preeclampsia group consisted of 21 women. Serum and umbilical cord samples of IL-6 were compared. Results: There was no significant difference between maternal and umbilical cord serum IL-6 concentrations between the preeclampsia and control group. No significant difference was observed in maternal and umbilical cord serum IL-6 levels between early- and late-onset preeclampsia groups. Conclusion: Our results do not support an increase in IL-6 levels in patients with early- and late-onset preeclampsia. The clinical relevance of our findings needs to be further investigated.     

Maternal and umbilical serum levels of interleukin-6, interleukin-8, and tumor necrosis factor-α in normal pregnancies and in pregnancies complicated by preeclampsia

Objectives.?The aim of this study was to investigate the relationship of maternal and umbilical cord interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α) serum levels with the existence and severity of preeclampsia. A particular objective was the comparison of normal umbilical serum levels to preeclamptic values.

Materials and Methods.?The study group consisted of 24 patients with third trimester singleton pregnancies complicated by preeclampsia (15 severe and 9 mild preeclampsia). The gestational age-matched 19 healthy pregnant women were compared by study group. Maternal and umbilical serum IL-6, IL-8, and TNF-α were calculated by using enzyme-linked immunosorbent assay.

Results.?Significantly increased maternal and umbilical serum levels of IL-6, IL-8, and TNF-α were found in preeclamptic patient group in comparison with the control group. Maternal serum IL-8 and TNF-α concentration were significantly higher in patients with severe preeclampsia than in mild preeclampsia. Increased umbilical serum levels of IL-6 and IL-8 were found in severe preeclampsia than in mild preeclampsia. There were significantly higher levels of maternal serum IL-8 and TNF-α in patients with preeclampsia with IUGR than in patients with preeclampsia with normal fetal growth.

Conclusion.?Our findings suggest that increased concentrations of IL-6, IL-8, and TNF-α in the maternal and umbilical serum play a significant role in pathogenesis of preeclampsia. Alterations in maternal and umbilical serum levels of IL-6, IL-8, and TNF-α may also play role in preeclampsia complicated by intrauterine growth retardation. These associations may offer insight into the etiology and pathogenesis of preeclampsia.     

Preeclampsia disrupts the normal physiology of leptin

This study was designed to examine the leptin levels of preeclamptic women and their offspring, to compare them with those of normal pregnant women and to search for a correlation between maternal and fetal plasma leptin levels and their anthropometric characteristics. Twenty-one preeclamptic women and their babies were enrolled into the study. Control group consisted of 21 normal pregnant women and their babies, whose birth weights, gestational ages, and genders match with those of babies born to preeclamptic women. Median maternal leptin concentrations of the preeclamptic group (15.3 ng/mL) were significantly higher ( p = 0.03) than the control group (10.4 ng/mL). However, fetal plasma leptin concentrations were not different ( p = 0.06) between the two groups. Fetal plasma leptin levels were correlated with birth weight, length, body mass index, gestational age, and fetal hematocrit levels in the control group. However, no correlation between leptin levels and these parameters was found in the preeclamptic group. Therefore, preeclampsia may be thought to disrupt normal leptin physiology.     

Extra-placental expression of vascular endothelial growth factor receptor-1, (Flt-1) and soluble Flt-1 (sFlt-1), by peripheral blood mononuclear cells (PBMCs) in normotensive and preeclamptic pregnant women

The soluble VEGF receptor, sFlt-1 (otherwise referred to as sVEGFR-1), has been implicated in the pathogenesis of preeclampsia. The preeclamptic placenta has been previously demonstrated to produce high levels of the soluble VEGF receptor. Here we tested the hypothesis that peripheral blood mononuclear cells (PBMCs) may also represent an additional source for circulating sFlt-1 during normal and preeclamptic pregnancies. We first demonstrate that preeclamptic placentae show five-fold increased Flt-1 and sFlt-1 mRNA levels. We also show that the Flt-1 and sFlt-1 levels are eight-fold higher in preeclamptic placentae if we collect biopsies without rinsing them in saline to remove excess blood. Cultured villous explants from women with preeclampsia failed to show the increased amount of Flt-1 and sFlt-1 mRNA that was observed in the placental biopsies of normal pregnancy and preeclampsia. Under normoxic conditions the Flt-1 and sFlt-1 mRNA levels in the explants were 3.11+/-0.6 fold in normal pregnancy and 3.6+/-0.4 fold in women with preeclampsia (p = NS by ANOVA). However, the same villous explants showed hypoxic induction of Flt-1 mRNA (NP 3.96+/-0.4 fold, p = NS and PE 5.24+/-0.6 fold, p < 0.05 by ANOVA). We analyzed Flt-1 and sFlt-1 protein levels in the peripheral blood mononuclear cells (PBMCs) to analyze the possibility of an extra-placental sFlt-1 source. Our results indicate that PBMCs of pregnant women are capable of expressing variable amounts of Flt-1 proteins. PBMCs from pregnant women exposed to hypoxia show up-regulation of HIF-1alpha and Flt-1 proteins. PBMCs obtained from women with preeclampsia (n = 9) produced significantly higher amounts of sFlt-1 under normal tissue culture conditions (104.6+/-14.3 pg/ml vs. 46.23+/-5.03 pg/ml, p < 0.05 by ANOVA) and much higher concentrations under hypoxia (196.74+/-26.3pg/ml vs. 83.3+/-13.6pg/ml, p < 0.05 by ANOVA) than PBMCs from normal pregnant women (n = 11). Moreover, analysis of PBMCs from a different group of women with a history of preeclampsia showed persistent abnormality of Flt-1 women one year post-partum. The present study indicates that Flt-1 dysregulation in PBMCs of pregnant women resulting in over-expression of sFlt-1 could be an additional (extra-placental) source of sFlt-1 that contributes to the pathogenesis of preeclampsia.     

Decreased maternal serum leptin in pregnancies complicated by preeclampsia

OBJECTIVE: To determine whether circulating levels of leptin differed between women with preeclampsia and women who had an uncomplicated pregnancy. METHODS: Maternal and umbilical venous plasma leptin concentrations obtained at delivery were compared in 36 pairs of women with either preeclampsia or normal pregnancy, matched 1:1 for prepregnancy body mass index and fetal gestational age at delivery. RESULTS: Prepregnancy body mass index was 21.1 +/- 2.1 kg/m2 in either study group (range 17.6-25.3 kg/m2 and 17.7-25.3 kg/m2 in the normal and preeclamptic group, respectively). Mean fetal gestational age at delivery was 40.1 +/- 1.3 weeks and 40.1 +/- 1.2 weeks in the normal and preeclamptic group, respectively. Median leptin concentrations were significantly lower (P <.0001) in women with preeclampsia (8.3 ng/mL, range 3.5-20.0 ng/mL) than in normal pregnant women (20.2 ng/mL, range 6.0-63.7 ng/mL). Median umbilical venous leptin was not significantly different between groups (preeclampsia 11.8 ng/mL, range 2.0-37.2 ng/mL; normal 7.6 ng/mL, range 1.6-24.3 ng/mL; P = .377). Umbilical venous leptin levels correlated positively with birth weight in both groups (preeclampsia rho = 0.501, P = .002; normal rho = 0.517, P = .001), whereas no correlations were found between maternal and fetal hormone concentrations. Maternal leptin concentrations did not correlate with birth weight. CONCLUSION: Our data suggest that the correlation between umbilical venous leptin concentration and birth weight is independent of the presence of preeclampsia. Given the inconsistency in literature concerning circulating leptin levels in preeclampsia, further studies should investigate the regulatory systems of leptin in preeclampsia.     

Maternal Serum Chlamydia Pneumoniae Antibodies and CRP Levels in Women with Preeclampsia and Gestational Hypertension

Objective. To determine whether Chlamydia pneumoniae antibodies and highly sensitive C-reactive protein (hsCRP) levels in maternal sera are associated with preeclampsia or gestational hypertension. Methods. C. pneumoniae antibodies and hsCRP levels were measured in maternal serum during first trimester (mean, 10.4 weeks of gestation) using the microimmunofluorescence (MIF) test and a highly sensitive immunoenzymometric assay, respectively. Results. No differences in the IgG antibody levels against C. pneumoniae or hsCRP levels were seen between the women with preeclampsia or gestational hypertension and those in the reference group. However, the women with preeclampsia and preterm delivery had serum IgG antibodies to C. pneumoniae (IgG titre ≥32) significantly more often in their first trimester sera compared with women having preeclampsia and full-term deliveries (p = 0.03). In addition, the proportion of subjects with C. pneumoniae IgG antibodies (IgG titre ≥32) and/or elevated CRP levels (≥3.8 mg/L, upper quartile) was double among the women with preeclampsia and elective preterm delivery compared with the women with preeclampsia who delivered at term (p = 0.01). Conclusion. Our results suggest that chronic C. pneumoniae infection and systemic low-grade inflammation may be associated with preeclampsia requiring elective delivery before 37 weeks gestation.     

Serum Levels of Alpha-Tocopherol in Hypertensive Pregnancies

Objective: Assess alpha-tocopherol serum levels in a population of pregnant women affected by different hypertensive disorders.

Methods: Alpha-tocopherol serum levels were determined by high-pressure liquid chromatography in 177 third-trimester pregnant women: 63 affected by gestational hypertension, 69 by preeclampsia, 26 by chronic hypertension, and 19 normotensive controls. In 39 out of the 158 hypertensive patients, pregnancy was complicated by intrauterine growth retardation (IUGR).

Results: Alpha-tocopherol serum levels did not show any significant difference among gestational hypertensive, preeclamptic, chronic hypertensive patients, and controls. A significant reduction of alpha-tocopherol levels was observed when we compared patients with IUGR and patients with a normally grown fetus. Such significant reduction was maintained when we analyzed the different classes of hypertension.

Conclusions: The reduction of antioxidant nutrients and, in particular, of alpha-tocopherol is not a feature of preeclampsia and seems better correlated with the presence of placental insufficiency, rather than maternal disease.     

Hypoxia Upregulates GCM1 in Human Placenta Explants

Studies in mice have shown that a variety of genes, including GCM1, regulate the differentiation of trophoblast cells. GCM1 is also expressed in the human placenta. Placental GCM1 protein has been reported to be reduced in preeclampsia. In view of the close link between hypoxia, hypoxia-reoxygenation, preeclampsia, placental development and the reported reduction in GCM1, we hypothesised that GCM1 expression would be affected by hypoxia. The aim was to determine the effects of hypoxia on GCM1 expression in the human placenta. Two model systems were used; villous explants and cultured primary cytotrophoblast cells. GCM1 protein was detectable at low levels in explants maintained for 7 h in 8 or 20% O₂. A striking increase in GCM1 was observed when villous explants were incubated for 1h in 1% O₂ (p < 0.002). Incubation of explants for 1 h in 1% O₂ followed by re-oxygenation for 6 h in 8 or 20% O₂ resulted in a decline in GCM1 protein. Expression of GCM1 was also analysed in primary cytotrophoblast and syncytiotrophoblast cultured in 8 or 20% O₂ or reduced oxygen (1–2% O₂) conditions. GCM1 protein was not detected in any of the experimental conditions used. This study has shown that acute hypoxia increases GCM-1 protein in villous explants. The experiments with purified trophoblast do not support a role for hypoxia increasing GCM-1 in these cells under the conditions used. The present findings are in keeping with the complex effects of oxygen depending on the conditions used. The hypoxic effects on GCM1 warrant further investigation as they may provide further information on the pathogenesis of preeclampsia.     

Differential expression of human placental PAPP-A2 over gestation and in preeclampsia

IntroductionPregnancy Associated Plasma Protein A2 (PAPP-A2) is a pregnancy related insulin-like growth factor binding protein-5 (IGFBP-5) protease, known to be elevated in preeclampsia. As the insulin-like growth factors are important in human implantation and placentation, we sought to determine the expression pattern of PAPP-A2 over human gestation in normal and preeclamptic pregnancies to evaluate its role in placental development and the pathogenesis of preeclampsia.MethodsPlacental basal plate and chorionic villi samples, maternal and fetal cord blood sera were obtained from preeclamptic and control pregnancies. Formalin-fixed tissue sections from across gestation were stained for cytokeratin-7, HLA-G, and PAPP-A2. PAPP-A2 immunoblot analysis was also performed on protein lysates and sera.ResultsPAPP-A2 expression is predominately expressed by differentiated trophoblasts and fetal endothelium. Chorionic villi show strong expression in the first trimester, followed by a progressive decrease in the second trimester, which returns in the third trimester. PAPP-A2 expression is not impacted by labor. PAPP-A2 is increased in the basal plate, chorionic villi and maternal sera in preeclampsia compared to controls, but is not detectable in cord blood.DiscussionPAPP-A2 is differentially expressed in different trophoblast populations and shows strong down regulation in the mid second trimester in chorionic villous samples. Both maternal sera and placental tissue from pregnancies complicated by preeclampsia show increased levels of PAPP-A2. PAPP-A2 levels are not altered by labor. Additionally, PAPP-A2 cannot be detected in cord blood demonstrating that the alterations in maternal and placental PAPP-A2 are not recapitulated in the fetal circulation.     

Alteration of integrins under hypoxic stress in early placenta and choriocarcinoma cell line BeWo

Invasion of the trophoblast into the decidua and the myometrium is very important for the establishment of a normal pregnancy. This invasion is regulated by the expression of integrins in the trophoblast. Recently, it has been shown that invasion of the trophoblast is impaired in preeclampsia. We report the effect of hypoxia on the expression of integrins and extracellular matrices at the mRNA level in early placenta and BeWo cells. Tissue RNA levels of fibronectin and integrin alpha5 were significantly higher in the hypoxic condition than under normoxic conditions. In contrast, tissue RNA levels of integrin alpha1 were significantly lower for the hypoxic condition than those under normoxic conditions. Alteration of the integrin components and increases in fibronectin expression were observed in early placenta and BeWo cells under hypoxic conditions. These results suggest that hypoxic stress regulates the synthesis of integrin and fibronectin mRNAs in early placenta.