Pre-eclampsia does not change the adhesion molecule status in the placental bed

CD39 abrogates platelet-derived factors induced IL-1β expression in the human placenta

Tissue insults in response to inflammation, hypoxia and ischemia are accompanied by the release of ATP into the extracellular space. There, ATP modulates several pathological processes, including chemotaxis, inflammasome induction and platelet activation. ATP hydrolysis is significantly enhanced in human pregnancy, suggesting that increased conversion of extracellular ATP is an important anti-inflammatory process in preventing exaggerated inflammation, platelet activation and hemostasis in gestation. Extracellular ATP is converted into AMP, and subsequently into adenosine by the two major nucleotide-metabolizing enzymes CD39 and CD73. Here, we aimed to elucidate developmental changes of placental CD39 and CD73 over gestation, compared their expression in placental tissue from patients with preeclampsia and healthy controls, and analyzed their regulation in response to platelet-derived factors and different oxygen conditions in placental explants as well as the trophoblast cell line BeWo. Linear regression analysis showed a significant increase in placental CD39 expression, while at the same time CD73 levels declined at term of pregnancy. Neither maternal smoking during first trimester, fetal sex, maternal age, nor maternal BMI revealed any effects on placental CD39 and CD73 expression. Immunohistochemistry detected both, CD39 and CD73, predominantly in the syncytiotrophoblast layer. Placental CD39 and CD73 expression were significantly increased in pregnancies complicated with preeclampsia, when compared to controls. Cultivation of placental explants under different oxygen conditions had no effect on the ectonucleotidases, whereas presence of platelet releasate from pregnant women led to deregulated CD39 expression. Overexpression of recombinant human CD39 in BeWo cells decreased extracellular ATP levels after culture in presence of platelet-derived factors. Moreover, platelet-derived factors-induced upregulation of the pro-inflammatory cytokine, interleukin-1β, was abolished by CD39 overexpression. Our study shows that placental CD39 is upregulated in preeclampsia, suggesting an increasing demand for extracellular ATP hydrolysis at the utero-placental interface. Increased placental CD39 in response to platelet-derived factors may lead to enhanced conversion of extracellular ATP levels, which in turn could represent an important anti-coagulant defense mechanism of the placenta.

Bile acids evoke placental inflammation by activating Gpbar1/NF-κB pathway in intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a cholestatic disorder with potentially deleterious consequences for fetuses. Although a clear correlation between the elevated levels of maternal serum bile acids and deficient fetal outcome has been established in clinical practice, the underlying mechanisms remain elusive. Herein, we report that bile acids induce NF-κB pathway activation via G protein-coupled bile acid receptor 1 (Gpbar1), with consequent upregulation of inflammatory genes in trophoblasts, leading to aberrant leukocyte infiltration and inflammation in placenta. Ursodeoxycholic acid (UDCA), a drug used clinically to treat ICP, competes with other bile acids for binding with Gpbar1 and thus inhibits bile acid-induced inflammatory response in trophoblasts and improves fetal survival in pregnant rats with obstructive cholestasis. Notably, inhibition of NF-κB by andrographolide is more effective than UDCA in benefiting placentas and fetuses. Thus, anti-inflammation therapy targeting Gpbar1/NF-κB pathway could be effective in suppressing bile acid-induced inflammation and alleviating ICP-associated fetal disorders.

Markers of endothelial cell dysfunction are increased in human omental adipose tissue from women with pre-existing maternal obesity and gestational diabetes

OBJECTIVE

To determine the effect of maternal obesity and gestational diabetes mellitus (GDM) on the expression and release of genes involved in endothelial cell dysfunction in human placenta and omental adipose tissue.

MATERIALS/METHODS

Human placenta and omental adipose tissue were obtained from non-obese and obese normal glucose tolerant (NGT) women and women with GDM at the time of Caesarean section. Quantitative RT-PCR was performed to determine the level of expression. Tissue explants were performed to determine the release of proteins of interest.

RESULTS

There was no effect of pre-existing maternal obesity or GDM on placental gene expression or secretion of members of the VEGF family members (PLGF and VEGF-A expression and secretion; sFlt-1 release; VEGFR1 and VEGFR2 mRNA expression); FGFR1 mRNA expression, FGF2 mRNA expression and secretion; endoglin mRNA expression and secretion (sEng); and the adhesion molecules ICAM-1 and VCAM-1. On the other hand, in omental adipose tissue, pre-existing maternal obesity and GDM were associated with increased gene expression of PLGF, endoglin and ICAM-1 and increased secretion of PLGF, sFlt-1, FGF2, sEng and sICAM-1. There was, however, no effect of maternal pre-existing obesity and GDM on VEGF-A, VEGFR1, VEGFR2, FGFR1 and VCAM-1 expression or secretion.

CONCLUSIONS

This study demonstrated the presence of abnormal expression and secretion of angiogenic proteins and adhesion molecules in omental adipose tissue, but not placenta, from pregnant women with GDM and pre-existing maternal obesity. Increased angiogenic and adhesion molecules released from adipose tissue may affect angiogenesis, inflammation and or lipid and glucose metabolism in both mum and her offspring.

Significance of platelet endothelial cell adhesion molecule-1 (PECAM-1) and intercellular adhesion molecule-1 (ICAM-1) expressions in preeclamptic placentae

Although preeclampsia (PE) is one of the most important problems affecting pregnant women, etiologic factors in its development are still unclear. We aimed to investigate the expression levels of platelet endothelial cell adhesion molecule-1 (PECAM-1) and intercellular adhesion molecule-1 (ICAM-1) in preeclamptic and control healthy placentas. Placental tissue samples were obtained after delivery from patients diagnosed with PE, and from normal term pregnants and analyzed by immunohistochemistry for the expression levels of the two adhesion molecules PECAM-1 and ICAM-1. A strong expression of PECAM-1 in endothelial cells lining the vessel walls of placental villi in placentas of control group was found, but the intensity of PECAM-1 expression was highly reduced in placentas of PE group (p = 0.017). Conversely, a strong expression of ICAM-1 was observed in placental villi in PE, significantly higher than that of normal placentas (p = 0.005). The findings of a decrease of PECAM-1 expression and an increase of ICAM-1 expression in preeclamptic placenta suggest the existence of functional roles of these adhesion molecules in the pathophysiology of PE, probably by contributing to the reduced trophoblast invasion and the increased vascular damage, respectively. Inhibiting ICAM-1 (i.e., with ICAM-1 monoclonal antibody) and promoting PECAM-1 expression may be good therapeutic approaches to prevent PE symptoms in the future.

Placental apoptosis and adhesion molecules expression in the placenta and the maternal placental bed of pregnancies complicated by fetal growth restriction with and without pre-eclampsia

The aim of the study was to examine the expression of adhesion molecules VCAM-1 and ICAM-3 in placental tissue samples and placental bed (maternal decidual tissue) biopsies of pregnancies complicated by pre-eclampsia (PE) and fetal growth restriction (FGR), and to determine whether PE and FGR are associated with an increase in placental apoptosis. We studied placentas and placental bed samples of 49 third trimester pregnancies complicated by FGR (26 with associated PE, 23 without PE) and 25 normotensive healthy pregnant women. Placental apoptosis was assessed by the TUNEL method. Immunohistochemistry was used to assess expression of the VCAM-1 and ICAM-3. There was no significant difference in the staining intensity of VCAM-1 in placentas (p=0.472) and placental bed biopsies (p=0.754) of women delivering appropriate for gestational age and growth restricted fetuses (with and without associated PE). The amount of lymphocytes staining positively with ICAM-3 was significantly higher in both placental and placental bed biopsies of women delivering growth restricted fetuses compared with control pregnancies (p<0.001). Fetal growth restricted pregnancies with associated PE showed higher staining of ICAM-3 in placental compared with placental bed samples (p=0.049). In fetal growth restricted placentas, apoptotic nuclei were more abundant compared with control placentas (p<0.001). Increased expression of ICAM-3 on lymphocyte surface of both maternal and fetal side, suggests lymphocyte overactivation in PE and FGR. Increased placental apoptosis may play an important role in the pathogenesis or sequelae of PE.

Intercellular adhesion molecule-1 expression in human endometrium: implications for long term progestin only contraception

BACKGROUND

Neutrophils infiltrate the endometrium pre-menstrually and after long-term progestin only-contraceptive (LTPOC) treatment. Trafficking of neutrophils involves endothelial cell-expressed intercellular adhesion molecule (ICAM-1). Previous studies observed that ICAM-1 was immunolocalized to the endothelium of endometrial specimens across the menstrual cycle, but disagreed as to whether extra-endothelial cell types express ICAM-1 and whether ICAM-1 expression varies across the menstrual cycle.

METHODS

Endometrial biopsies were obtained from women across the menstrual cycle and from those on LTPOC treatment (either Mirena or Norplant). The biopsies were formalin-fixed and paraffin-embedded with subsequent immunohistochemical staining for ICAM-1.

RESULTS

The current study found prominent ICAM-1 staining in the endometrial endothelium that was of equivalent intensity in different blood vessel types irrespective of the steroidal or inflammatory endometrial milieu across the menstrual cycle and during LTPOC therapy. Unlike the endothelial cells, the glands were negative and the stromal cells were weakly positive for ICAM immunostaining.

CONCLUSION

The results of the current study suggest that altered expression of ICAM-1 by endothelial cells does not account for the influx of neutrophils into the premenstrual and LTPOC-derived endometrium. Such neutrophil infiltration may depend on altered expression of neutrophil chemoattractants.

Microvascular endothelial cell activation is present in the umbilical placental microcirculation in fetal placental vascular disease

OBJECTIVE

Fetal growth restriction is associated with an abnormal umbilical artery Doppler study. A vascular disease is present in the fetal umbilical placental microcirculation. We hypothesized that the local production of factors that are injurious to microvessel endothelium is responsible for this vascular disease and that endothelial cell activation is a feature of this. Because the expression of the cell adhesion molecules is associated with endothelial cell activation, we isolated endothelial cells from the microvessels of the umbilical placenta and examined them for evidence of gene expression of cell adhesion molecules.

STUDY DESIGN

Endothelial cells from the microcirculation of human placenta were isolated and purified with collagenase digestion and extraction with superparamagnetic beads that were coated with monoclonal antibody against CD31. Microvessel endothelial cells were isolated from the placentae of 13 women with a normal pregnancy and delivery at term and 10 placentas with umbilical placental vascular disease that was defined by abnormal umbilical artery Doppler study. Total RNA was extracted from isolated endothelial cells. The messenger RNA expressions of cell adhesion molecules (intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and platelet endothelial cell adhesion molecule-1) were assessed by semiquantitative reverse transcription-polymerase chain reaction.

RESULTS

Microvessel endothelial cells from the fetal placentae of pregnancies that were complicated by umbilical placental vascular disease showed an enhanced expression of intercellular adhesion molecule-1 messenger RNA (2.12+/-0.45 vs 0.92+/-0.25) and platelet endothelial cell adhesion molecule-1 messenger RNA (4.29+/-0.87 vs 2.41+/-0.42) in comparison to normal pregnancies. There was no significant difference in expression of vascular cell adhesion molecule-1 messenger RNA (1.55+/-0.37 vs 1.68+/-0.38).

CONCLUSION

We have shown that vascular disease in the fetal umbilical placental circulation is associated with an increase in the expression of intercellular adhesion molecule-1 and platelet endothelial cell adhesion molecule-1 by microvessel endothelial cells. We postulate that locally released factors cause injury and activation to microvessel endothelial cells. In this regard, the process in the fetus is similar to that of atherothrombotic vascular disease of later life.

Role of placenta in preeclampsia

Preeclampsia, which manifests itself as hypertension, proteinuria, and edema in pregnancy, requires the presence of trophoblast tissue but not a fetus. It is characterized by abnormal trophoblast invasion of the spiral arteries of the decidua and myometrium leading to a failure to establish an adequate uteroplacental blood flow and, therefore, is thought to give rise to relatively hypoxic trophoblast tissue. This, in turn, may promote an exaggerated state of oxidative stress in the placenta. This hypoxia/oxidative stress may then further attenuate trophoblast invasion but also alters placental villous angiogenesis leading to a poorly developed fetoplacental vasculature with abnormal reactivity. Oxidative stress per se may also affect vascular reactivity, blood flow, and oxygen and nutrient delivery to the fetus, which ultimately may be compromised. The synthetic and transport functions of the syncytiotrophoblast may also be altered, and there is an increased rate of trophoblast apoptosis. The linkage among abnormal trophoblast invasion, trophoblast dysfunction, and the maternal disease remains unidentified. The presumptive humoral factor that is released by the preeclamptic placenta to cause maternal disease remains elusive. Current therapies to prevent preeclampsia aim toward preventing the maternal syndrome, not preventing the primary pathophysiology.

Soluble adhesion molecule profile in normal pregnancy and pre-eclampsia

OBJECTIVE

An exaggerated inflammatory response has been implicated as the cause of endothelial cell dysfunction and the maternal syndrome of pre-eclampsia. Adhesion molecules play a central role in the adherence of leukocytes to endothelial cells and the subsequent migration of white blood cells into perivascular tissue. Cellular forms of adhesion molecules mediate specific steps of leukocyte-endothelial cell interaction, and have been implicated in the pathophysiology of preeclampsia. Soluble forms of these molecules can be detected in plasma, and their concentrations are thought to reflect the degree of activation of a particular cell type. Elevations in soluble P-selectin (sP-selectin) reflect platelet activation; changes in soluble L-selectin (sL-selectin) suggest leukocyte activation; and an increase in soluble forms of E-selectin (sE-selectin), vascular cell adhesion molecule 1 (sVCAM-1), intercellular adhesion molecule 1 (sICAM-1) and platelet endothelial cell adhesion molecule (sPECAM-1) indicate endothelial cell activation/dysfunction. The objective of this study was to determine whether normal pregnancy and pre-eclampsia were associated with changes in the concentrations of soluble selectins and members of the immunoglobulin superfamily of adhesion molecules.

STUDY DESIGN

A cross-sectional study was conducted to determine the plasma concentrations of sL-selectin, sE-selectin, sP-selectin, sVCAM-1, sICAM-1 and sPECAM-1 in peripheral blood obtained from non-pregnant women (n = 20), normal pregnant women (n = 100) and patients with pre-eclampsia (n = 55). Concentrations of soluble adhesion molecules were determined with enzyme-linked immunoassays. Parametric statistics were used for data analysis.

RESULTS

Normal pregnancy was associated with a significant increase in the maternal plasma concentration of sP-selectin, a decrease in sL-selectin, and no change in sE-selectin, sVCAM-1, sICAM-1 and sPECAM-1. In contrast, pre-eclampsia was associated with a significant increase in sP-selectin, sE-selectin and sVCAM-1, a decrease in sL-selectin, but no change in sICAM-1 and sPECAM-1 concentrations.

CONCLUSIONS

The increased concentration of sP-selectin and decreased sL-selectin, as well as the lack of change in endothelial cell-associated soluble adhesion molecules suggest that pregnancy is associated with platelet and leukocyte activation, but not endothelial cell activation. In contrast, pre-eclampsia appears to be characterized by activation of platelets, leukocytes and endothelial cells.

Predictive value of hormone measurements in maternal and fetal complications of pregnancy

Intrauterine tissues (placenta, amnion, chorion, decidua) express hormones and cytokines that play a decisive role in maternal-fetal physiological interactions. The excessive or deficient release of some placental hormones in association with gestational diseases may reflect an abnormal differentiation of the placenta, an impaired fetal metabolism, or an adaptive response of the feto-placental unit to adverse conditions. This review is focused on the applicability of hormone measurements in the risk assessment, early diagnosis, and management of pregnancies complicated by Down's syndrome, fetal growth restriction, preeclampsia, preterm delivery, and diabetes mellitus. Combined hormonal tests or the combination of hormones and ultrasound may achieve reasonable sensitivity, but research continues to simplify the screening programs without sacrificing their accuracy. Only in a few instances is there sufficient evidence to firmly recommend the routine use of hormone tests to predict maternal and fetal complications, but the judicious use of selected tests may enhance the sensitivity of the risk assessment based solely on clinical and ultrasound examination.

Adhesion molecules expression in the placental bed of pregnancies with pre-eclampsia

OBJECTIVE

To compare the expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), platelet endothelial cell adhesion molecule-1 (PECAM-1) and E-selectin in placental bed biopsies (endothelium of spiral arteries as well as trophoblastic cells) from normal and pre-eclamptic pregnancies.

DESIGN

A prospective study.

SETTING

1. First Department of Obstetrics and Gynaecology, Alexandra Hospital, University of Athens, Greece. 2. Laboratory of Pathophysiology, Laikon Hospital, University of Athens.

POPULATION

Sixteen placental bed biopsies from women with pre-eclampsia were compared with 20 placental bed biopsies from uncomplicated normotensive women.

MAIN OUTCOME MEASURES

Immunocytochemical staining of the placental bed biopsies for ICAM-1, VCAM-1, PECAM-1 and E-selectin.

RESULTS

No statistically significant differences were found in the expression of the adhesion molecules ICAM-1, VCAM-1, PECAM-1 and E-selectin in the endothelium of the spiral arteries and the trophoblastic cells of the placental bed of the two studied groups.

CONCLUSIONS

Adhesion molecules ICAM-1, VCAM-1, PECAM-1, but not E-selectin, are expressed in the placental bed of normal and pre-eclamptic pregnancies, but there are no differences between the two groups of women. It seems that the above molecules are not likely to be implicated in the aetiology of pre-eclampsia.

The relationship between the level of expression of intercellular adhesion molecule-1 in placenta and onset of preeclampsia

OBJECTIVE

To investigate the differences in the expression of intercellular adhesion molecule-1 (ICAM-1) in the placenta and the concentration of soluble ICAM-1 between early-onset and late-onset preeclampsia.

METHODS

Preeclampsia was divided into early-onset type (EO: 20 to 31 weeks gestation) and late-onset type (LO: > or = 32 weeks gestation). Post delivery, placentas were obtained from 19 control pregnant women and from 9 EO and 8 LO preeclamptic women. The expression of ICAM-1 in placenta was determined by immunohistochemical staining. Blood samples were taken from 21 non-pregnant women, 16 control pregnant women, 13 EO and 8 LO preeclamptic women, and umbilical cord blood samples from 38 control pregnancies and from 16 EO and 14 LO preeclampsia. The concentration of ICAM-1 was measured by enzyme-linked immunosorbent assays.

RESULTS

The expression of ICAM-1 in placenta was higher in LO than in EO preeclampsia (48.2 +/- 8.2% vs 17.9 +/- 5.0%) (p < 0.05). ICAM-1 concentration in umbilical cord blood was higher in EO than in LO preeclampsia (umbilical artery, 150.6 +/- 34.0 ng/ml vs 90.3 +/- 9.4 ng/ ml) (umbilical vein, 128.3 +/- 31.2 ng/ml vs 91.3 +/- 10.2 ng/ml) (p < 0.05).

CONCLUSIONS

Significant differences were noted in the expression of ICAM-1 between patients with EO and LO preeclampsia, which suggest that the possibility that EO and LO preeclampsia may have different onset mechanisms.