Intercellular adhesion molecule-1 (ICAM-1) and HLA-DR antigens are expressed on endovascular cytotrophoblasts in abnormal pregnancies

Cellular immune responses in the pathophysiology of preeclampsia

Preeclampsia, defined as new-onset hypertension accompanied by proteinuria occurring at 20 weeks of gestation or later, is a leading cause of perinatal morbidity and mortality worldwide. The pathophysiology of this major multi-systemic syndrome includes defective deep placentation, oxidative stress, endothelial dysfunction, the presence of an anti-angiogenic state, and intravascular inflammation, among others. In this review, we provide a comprehensive overview of the cellular immune responses involved in the pathogenesis of preeclampsia. Specifically, we summarize the role of innate and adaptive immune cells in the maternal circulation, reproductive tissues, and at the maternal-fetal interface of women affected by this pregnancy complication. The major cellular subsets involved in the pathogenesis of preeclampsia are regulatory T cells, effector T cells, NK cells, monocytes, macrophages, and neutrophils. We also summarize the literature on those immune cells that have been less characterized in this clinical condition, such as γδ T cells, invariant natural killer T cells, dendritic cells, mast cells, and B cells. Moreover, we discuss in vivo studies utilizing a variety of animal models of preeclampsia to further support the role of immune cells in this disease. Finally, we highlight the existing gaps in knowledge of the immunobiology of preeclampsia that require further investigation. The goal of this review is to promote translational research leading to clinically relevant strategies that can improve adverse perinatal outcomes resulting from the obstetrical syndrome of preeclampsia.

Pathogenesis of uteroplacental acute atherosis: An update on current research

Uteroplacental acute atherosis is a type of arterial vascular disease that affects the placenta during pregnancy and predominates in the maternal spiral arteries in the decidua basalis layer of the pregnant uterus. This condition is characterized by fibrin-like necrosis of the blood vessel walls, the accumulation of macrophages containing fat (foam cells), and the infiltration of macrophages around blood vessels. Uteroplacental acute atherosis is rare in normal pregnancy but occurs more frequently in patients with pregnancy complications, including preeclampsia, spontaneous preterm labor, preterm prelabor rupture of membranes, mid-trimester spontaneous abortion, fetal death, and small-for-gestational age. It is believed that the mechanisms underlying the development of uteroplacental acute atherosis are related to the incomplete physiological transformation of spiral arteries, placental inflammation, abnormal lipid metabolism, and oxidative stress. In this review, we describe the pathogenesis of uteroplacental acute atherosis to provide reference guidelines for the future prevention and treatment of uteroplacental acute atherosclerotic disease.

Role of Human Leukocyte Antigens at the Feto-Maternal Interface in Normal and Pathological Pregnancy: An Update

The successful maternal tolerance of the semi-allogeneic fetus provides an apparent immunologic paradox. Indeed, deep invasion of placental trophoblast cells into maternal uterine tissue and the following growth of the fetus have to be tolerated by a pregnant woman’s immune system. Among the various possible protective mechanisms that may be involved in human pregnancy, the expression of a non-classical pattern of human leukocyte antigen (HLA) class I molecules and the complete lack of expression of HLA class II molecules in placental tissues seem to be the most relevant mechanisms of fetal escape from maternal immune recognition. The importance of HLA molecules in fetal toleration by the maternal immune system is highlighted by pregnancy complications occurring in cases of abnormal HLA molecule expression at the maternal–fetal interface. In this review, we summarize evidences about the role of placental HLA molecules in normal and pathological pregnancies.

HLA-DR is aberrantly expressed at feto-maternal interface in pre-eclampsia

In normal pregnancy, villous cytotrophoblast and syncytiotrophoblast do not express HLA Class I and Class II molecules, while invasive extravillous trophoblast only express class I HLA-C and the atypical class Ib antigens, HLA-G, -E and -F. Inadequate maternal tolerance of invasive trophoblast has been proposed as a possible immunologic trigger of poor trophoblast invasion and subsequent occurrence of pre-eclampsia. This study aimed to investigate possible aberrant expression of class II HLA-DR on placentae and syncytiotrophoblast-derived extracellular vesicles (STEVs), obtained by dual placental perfusion, from pre-eclampsia (n = 23) and normal pregnant (n = 14) women. Here we demonstrate that HLA-DR can be detected in syncytiotrophoblast from a significant proportion of pre-eclampsia but not control placentae. HLA-DR was also observed, by flow cytometry, on STEVs and associated with placental alkaline phosphatase to validate their placental origin. HLA-DR positive syncytiotrophoblast was detected in placental biopsies from pre-eclampsia but not normal control cases, using immunohistochemistry. The HLA may be fetal or maternal origin. In the latter case a possible mechanism of acquisition is trogocytosis.

The profiles of soluble adhesion molecules in the "great obstetrical syndromes". J Matern Fetal Neonatal Med 2018;32:2113-2136. [PMID: 29320948 DOI: 10.1080/14767058.2018.1427058]

OBJECTIVE

The objective of this study was to determine the profiles of maternal plasma soluble adhesion molecules in patients with preeclampsia, small-for-gestational-age (SGA) fetuses, acute pyelonephritis, preterm labor with intact membranes (PTL), preterm prelabor rupture of the membranes (preterm PROM), and fetal death.

MATERIALS AND METHODS

A cross-sectional study was conducted to determine maternal plasma concentrations of sE-selectin, sL-selectin, and sP-selectin as well as sICAM-1, sVCAM-1, and sPECAM-1 in patients with (1) an uncomplicated pregnancy (control, n = 100); (2) preeclampsia (n = 94); (3) SGA fetuses (in women without preeclampsia/hypertension, n = 45); (4) acute pyelonephritis (n = 25); (5) PTL (n = 53); (6) preterm PROM (n = 24); and (7) fetal death (n = 34). Concentrations of soluble adhesion molecules and inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-8) were determined with sensitive and specific enzyme-linked immunoassays.

RESULTS

In comparison to women with a normal pregnancy, (1) women with preeclampsia had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1, and a lower concentration of sL-selectin (all p values < .001); (2) patients with SGA fetuses had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1 (all p values < .05); (3) patients with a fetal death had higher median concentrations of sE-selectin and sP-selectin (all p values < .05); (4) patients with acute pyelonephritis had higher median plasma concentrations of sE-selectin, sICAM-1, and sVCAM-1 (all p values < .001); (5) patients with preeclampsia and acute pyelonephritis, plasma concentrations of sVCAM-1, sE-selectin, and sP-selectin correlated with those of the proinflammatory cytokines TNF-α and interleukin (IL)-8 (all p values < .05); (6) patients with PTL had a higher median concentration of sP-selectin and a lower median concentration of VCAM-1 (all p values < .05); and (7) women with preterm PROM had lower median concentrations of sL-selectin and sVCAM-1 (all p values < .05).

CONCLUSIONS

The results of this study show that endothelial cell activation/dysfunction reflected by the plasma concentration of sE-selectin is not specific to preeclampsia but is present in pregnancies complicated by SGA fetuses, acute pyelonephritis, and fetal death. Collectively, we report that each obstetrical syndrome appears to have a stereotypical profile of soluble adhesion molecules in the peripheral circulation.

Failure of physiologic transformation of spiral arteries, endothelial and trophoblast cell activation, and acute atherosis in the basal plate of the placenta

BACKGROUND

Failure of physiologic transformation of spiral arteries has been reported in preeclampsia, fetal growth restriction, fetal death, and spontaneous preterm labor with intact or ruptured membranes. Spiral arteries with failure of physiologic transformation are prone to develop atherosclerotic-like lesions of atherosis. There are striking parallels between preeclampsia and atherosclerotic disease, and between lesions of atherosis and atherosclerosis. Endothelial activation, identified by intercellular adhesion molecule-1 expression, is present in atherosclerotic-like lesions of heart transplantation, and is considered a manifestation of rejection. Similarly, endothelial activation/dysfunction has been implicated in the pathophysiology of atherosclerosis and preeclampsia. Intercellular adhesion molecule-1-overexpressing-activated endothelial cells are more resistant to trophoblast displacement than nonactivated endothelium, and may contribute to shallow spiral artery trophoblastic invasion in obstetrical syndromes having failure of physiologic transformation.

OBJECTIVE

We sought to determine whether failure of spiral artery physiologic transformation was associated with activation of interstitial extravillous trophoblasts and/or spiral artery endothelium and presence of acute atherosis in the placental basal plate.

STUDY DESIGN

A cross-sectional study of 123 placentas (19-42 weeks' gestation) obtained from normal pregnancies (n = 22), preterm prelabor rupture of membranes (n = 26), preterm labor (n = 23), preeclampsia (n = 27), intrauterine fetal death (n = 15), and small for gestational age (n = 10) was performed. Failure of spiral artery physiologic transformation and presence of cell activation was determined using immunohistochemistry of placental basal plates containing a median of 4 (minimum: 1; maximum: 9) vessels per placenta. Endothelial/trophoblast cell activation was defined by the expression of intercellular adhesion molecule-1. Investigators examining microscopic sections were blinded to clinical diagnosis. Pairwise comparisons among placenta groups were performed with Fisher exact test and Wilcoxon rank sum test using a Bonferroni-adjusted level of significance (.025).

RESULTS

We found that 87% (94/108) of placentas having spiral arteries with failure of physiologic transformation (actin-positive and cytokeratin-negative) in the basal plate, and 0% (0/15) of placentas having only spiral arteries with complete physiologic transformation (cytokeratin-positive and actin-negative), had arterial endothelial and/or interstitial extravillous trophoblasts reactive with the intercellular adhesion molecule-1 activation marker (P < .001). A significant correlation (R² = 0.84) was found between expression of spiral artery endothelial and interstitial extravillous trophoblast intercellular adhesion molecule-1 (P < .001) in activated placentas. Lesions of atherosis were found in 31.9% (30/94) of placentas with complete and/or partial failure of physiologic transformation of spiral arteries that were intercellular adhesion molecule-1-positive, in none of the 14 placentas with failure of physiologic transformation that were intercellular adhesion molecule-1-negative, and in none of the 15 placentas with complete spiral artery physiologic transformation without failure (P = .001). All placentas (30/30, 100%) with atherosis were identified in placentas having concomitant spiral artery endothelial and interstitial extravillous trophoblast activation.

CONCLUSION

Failure of spiral artery physiologic transformation in the placental basal plate is associated with interstitial extravillous trophoblast and arterial endothelial activation along with increased frequency of spiral artery atherosis. These findings may be used to improve the characterization of different disorders of the placental bed such as in refining the existing tools for the early prediction of risk for preterm, preeclamptic, and other abnormal pregnancies.

Circulating cell-derived microparticles in severe preeclampsia and in fetal growth restriction

PROBLEM

The behavior of the circulating microparticles (cMP) in severe preeclampsia (PE) and fetal growth restriction (FGR) is disputed. METHOD OF STUDY  Non-matched case-control study. Seventy cases of severe PE/HELLP/FGR were compared to 38 healthy pregnant women. Twenty healthy non-pregnant women acted as a control. cMP were analyzed using flow cytometry. Results are given as total (annexin-A5-ANXA5+), platelet (CD41+), leukocyte (CD45+), endothelial (CD144+CD31+//CD41-), and CD41-negative cMP/μL of plasma. Antiphospholipid antibodies (aPL) were analyzed through usual methods.

RESULTS

Platelet and endothelial cMP increased in healthy pregnant women. PE whole group (PE±FGR) showed an increase in endothelial and CD41-negative, but not in platelet-derived, cMP. Comparing PE whole group versus healthy pregnant, we found cMP levels of endothelial and CD41- had increased. The cMP results obtained in PE group were similar to those of the PE whole group. Comparing PE group to isolated FGR, significant CD41-negative cMP increase was found in PE. According to its aPL positivity, a trend to decrease in leukocyte and endothelial-derived cMP was found in PE group.

CONCLUSION

Normal pregnancy is accompanied by endothelial and platelet cell activation. Endothelial cell activation has been shown in PE but not in isolated FGR. In PE, aPL may contribute to endothelial and possibly to leukocyte cell activation.

Periodontal pathogen Aggregatibacter actinomycetemcomitans LPS induces mitochondria-dependent-apoptosis in human placental trophoblasts

OBJECTIVE

Increasing evidence suggests an association between periodontal disease and low birthweight (LBW); however the underlying molecular mechanisms are yet to be fully elucidated. In this study, we performed a microarray analysis to observe the human placental trophoblast-like BeWo cells response to lipopolysaccharide (LPS) from periodontopathogen Aggregatibacter actinomycetemcomitans (Aa), in order to investigate the molecular basis of mechanisms for periodontitis-associated LBW. In vivo pregnant rats were also used to confirm the in vitro results.

STUDY DESIGN

The effects of Aa-LPS on cultured human placental trophoblast-like BeWo cells were studied using a DNA microarray, Ingenuity Pathway Analysis, real-time PCR and poly-caspase staining. The in vivo effects of Aa-LPS in pregnant rats were examined using TUNEL assays.

RESULTS

In BeWo cells, Aa-LPS increased levels of cytochrome c, caspase 2, caspase 3, caspase 9 and BCL2-antagonist/killer 1 mRNA, decreased those of B-cell CLL/lymphoma 2, BCL2-like 1 and catalase mRNA and increased poly-caspase activity, all of which are consistent with activation of the mitochondria-dependent apoptotic pathway. TUNEL assays confirmed the increased incidence of apoptosis in placentas of Aa-LPS-treated rats (p < 0.001).

CONCLUSION

Aa-LPS induces apoptosis in human trophoblasts via the mitochondria-dependent pathway, and this effect may contribute to the pathogenesis of periodontitis-associated LBW.

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.

Neutrophil-derived reactive oxygen species can modulate neutrophil adhesion to endothelial cells in preeclampsia

BACKGROUND

Neutrophil activation has been implicated in the pathophysiology of preeclampsia. The aim of this study was to investigate whether neutrophil-derived reactive oxygen species (ROS) modulate adhesion to endothelial cells in preeclampsia.

METHODS

We first assessed neutrophil superoxide production and neutrophil-endothelial cell adhesion in normal nonpregnant women (n = 8), normal pregnant women (n = 10), and preeclamptic pregnant women (n = 8). We then examined the effects of neutrophil-derived ROS on neutrophil-endothelial adhesion. The release of neutrophil superoxide was measured using cytochrome C reduction.

RESULTS

N-formyl-methionyl-leucyl-phenylalanine (FMLP)-stimulated superoxide production by neutrophils was significantly increased in women with preeclampsia when compared with the other two groups. Neutrophils from women with preeclampsia were more likely to adhere to endothelial cells, than were those from the other two groups (mean adhesion rate +/- s.d. (%); 20.6 +/- 2.7 in preeclampsia, 10.2 +/- 1.2 in normal pregnancy, 11.0 +/- 0.9 in normal nonpregnancy, P < 0.01). Superoxide dismutase (SOD), which dismutates the excess superoxide to hydrogen peroxide, did not affect neutrophil-endothelial adhesion. In contrast, catalase, which catalyzes the conversion of hydrogen peroxide to oxygen and water, inhibited neutrophil-endothelial adhesion in the preeclamptic group (8.1 +/- 0.5%, P < 0.01).

CONCLUSION

Neutrophils from women with preeclampsia demonstrate increased CD11b expression and adhesion to endothelial cells. This is likely caused by elevations in superoxide and its derivative, hydrogen peroxide.

Cytokine regulation of intercellular adhesion molecule-1 expression on trophoblasts in preeclampsia

In normal pregnancy, trophoblast (TR) invasion plays a crucial role in remodeling the spiral arteries to develop uteroplacental circulation. Disruption of this invasion is associated with deficient uteroplacental circulation, which can lead to the development of preeclampsia (PE) through abnormal expression of adhesion molecules in the placenta and high serum causative factors such as cytokines. We aimed to evaluate whether serum factors in PE influence intercellular adhesion molecule-1 (ICAM-1) expression of TRs. ICAM-1 expression of TRs was measured using flow cytometry and immunohistochemistry was performed to examine the localization of tumor necrosis factor-alpha (TNFalpha) and ICAM-1 in placentas derived from women with normal pregnancies and women with PE. Sera from PE patients significantly increased ICAM-1 expression on TRs compared to sera from normal pregnant women; this increase was blocked with an antibody to TNFalpha. TNFalpha also enhanced ICAM-1 expression on TRs through nuclear factor-kappaB activation. We conclude that ICAM-1 expressed on TRs is involved in PE pathogenesis and is regulated by cytokines.

Intracellular adhesion molecule concentrations in women who smoke during pregnancy

OBJECTIVE

Smoking and endothelial dysfunction are associated with adverse pregnancy outcomes. The effect of smoking on vascular endothelium during pregnancy has not been well studied. Our objectives were to determine if smoking has an impact on endothelial function in pregnancy by comparing markers of endothelial function and to evaluate the contribution from different cellular sources.

METHODS

We measured markers of endothelial function in a prospective cohort of 198 primiparous women who had 325 plasma samples obtained throughout pregnancy. Samples were assayed for intracellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and E-selectin. Smoking status was determined by serum cotinine concentration. Analyses of adhesion molecules were performed for 4 gestational age intervals by using Mann-Whitney and Kruskal-Wallis tests. Gene expression for ICAM-1 was determined by real-time polymerase chain reaction from placental biopsies. A human umbilical vein endothelial cell (HUVEC) culture model was utilized to evaluate the effect of cotinine on endothelial cell production of ICAM-1.

RESULTS

ICAM-1 is increased, VCAM-1 was not different, and E-selectin was decreased among smokers at various times during pregnancy. Placental production of ICAM-1 was decreased in women who smoked (P = .02) as measured by real-time polymerase chain reaction. Human umbilical vein endothelial cells production of ICAM-1 increased with heavy concentrations of cotinine exposure (P < .01).

CONCLUSION

Smoking during pregnancy is associated with vascular perturbations, as evidenced by increased concentrations of serum ICAM-1. It appears unlikely that the source of the increased ICAM-1 is the placenta. The endothelium most likely contributes to increased maternal ICAM-1 in heavy smokers, but a leukocyte source cannot be ruled out.

LEVEL OF EVIDENCE

II-2.

Mechanisms regulating cytotrophoblast invasion in normal pregnancy and pre-eclampsia

The placental bed underlies the placenta and includes the decidua basalis and underlying myometrium containing the uterine spiral arteries. For successful human haemochorial placentation, the placental bed spiral arteries must undergo considerable alterations. These physiological modifications are thought to be brought about by the interaction of invasive cytotrophoblast with the spiral artery vessel wall. Failure of spiral artery transformation is thought to play an important role in the sequence of events that gives rise to pre-eclampsia. The mechanisms that control human trophoblast invasion in normal, let alone abnormal pregnancy, are still poorly understood. Much of the information on the early physiological changes within the placental bed comes from studies on intact hysterectomy specimens.(1) Details of such events in late pregnancy and in pregnancies complicated by pre-eclampsia and fetal growth restriction are principally derived from the study of placental bed biopsies taken at Caesarean section. The methods of sampling the placental bed have been reviewed elsewhere.(2) Many investigators have relied on in vitro models of trophoblast invasion. In vitro models can be extremely useful in dissecting out some of these processes but may be open to artefacts. The mechanisms underlying normal and failed trophoblast invasion appear to be complex. In this manuscript the mechanisms that control the invasion of trophoblast into the decidua and myometrium are reviewed. Along with this is a review of the purported mechanisms underlying failed spiral artery transformation. Particular emphasis has been placed on topics that have been best studied.

Genetic origin and proportion of basal plate surface-lining cells in normal and abnormal pregnancies

The human placenta is a transient organ, the villous surface of which is in direct contact with the maternal circulation during pregnancy. Thus, the syncytiotrophoblast and the basal plate-lining cells are considered continuous with the endothelial layer of the maternal vasculature. Two types of cells are found on the surface of the basal plate: trophoblasts (of fetal origin) and endothelial cells of putative maternal origin. Histologic abnormalities have been described in the basal plate of the placenta obtained from patients with preeclampsia and intrauterine growth restriction. Moreover, endothelial cell dysfunction and intravascular inflammation are key features of preeclampsia. The objectives of this study were to: (1) determine the origin of the endothelial cells located in the basal plate surface of the placenta (from male fetuses); and (2) analyze the relative proportion of the intervillous surface of the basal plate occupied by trophoblasts and endothelial cells. Immunohistochemistry and morphometry were performed in placentas from women in the following clinical groups: (1) normal-term pregnancies (n = 15); (2) severe preeclampsia at term (n = 15); (3) small-for-gestational-age (SGA) neonates delivered at term (n = 15); (4) preterm deliveries (<37 weeks) without inflammation (n = 5); and (5) preterm preeclampsia (n = 5). Laser capture microdissection and polymerase chain reaction were used to determine the allelic pattern of the amelogenin gene of the endothelial cells on the intervillous surface of the basal plate. Our results showed that: (1) the endothelial cells lining the basal plate in placentas of male fetuses were uniformly of maternal origin; and (2) in placentas from uncomplicated pregnancies, the median proportion of trophoblasts and endothelial cells covering the surface of the basal plate were 27.7% and 46.5%, respectively. The remaining area of the intervillous surface of the basal plate was composed of fibrin and anchoring villi. Of interest, placentas from women who delivered an SGA neonate had a higher proportion of trophoblasts and a lower proportion of endothelial cells lining the basal plate than those from normal pregnancies (P < .05). The same tendency was observed in placentas from patients with preeclampsia. This study demonstrates that endothelial cells of maternal origin cover the intervillous surface of the basal plate of the placenta, along with trophoblasts of fetal origin. The proportion of this surface lined by trophoblasts is greater in placentas from SGA and preeclampsia than in normal pregnancy. We propose that this change reflects a compensatory mechanism whereby the basal plate surface covered by injured endothelial cells is replaced by trophoblasts or results from a failure of trophoblastic involution in abnormal pregnancies. Our observations also suggest that the lining of the basal plate can provide information about the pathology of endothelial cells in complications of pregnancy.

Tumor suppressor and growth regulatory genes are overexpressed in severe early-onset preeclampsia--an array study on case-specific human preeclamptic placental tissue

BACKGROUND

Preeclampsia is an important clinical condition with unknown etiology. We used DNA array technique to compare placental gene expression profile in severe early-onset preeclampsia from 25 to 27 gestational weeks with strictly non-affected placental samples from similar gestational weeks.

METHOD

DNA arrays were validated by showing the up-regulation of several genes typical for preeclampsia such as chorionic gonadotrophin beta-chain, tissue factor pathway inhibitor, and intercellular adhesion molecule-1. In DNA array, 5% of genes displayed less than or equal to twofold increase in expression level and only 0.2% of genes showed < or =0.5-fold decrease in expression in preeclampsia versus control. Signs of immunological factors, hypoxia, apoptosis, oxidative stress and altered thrombosis, coagulation as well as endothelial injury were seen in the gene expression profile.

RESULTS

As a new finding, we identified a group of 13 genes with a function in tumor suppression and growth regulation which were significantly up-regulated in preeclampsia. Three out of the five most highly up-regulated genes belonged to this group which included genes, such as protein phosphatase 2, phospholipid scramblase 1, transcription elongation factor, melanoma adhesion molecule, retinoic acid receptor responder 3, and RANTES.

CONCLUSIONS

It is concluded that up-regulation of tumor suppressor and growth regulatory genes may play an important role in the pathogenesis of severe early-onset preeclampsia.

Smoking during pregnancy is associated with alterations in markers of endothelial function

OBJECTIVE

Alterations in endothelial function may explain the reduced risk of preeclampsia that is associated with smoking. We hypothesized that markers of endothelial function increase over pregnancy but decrease with smoking.

STUDY DESIGN

Plasma samples were obtained throughout pregnancy from 63 primiparous women with normal pregnancies. The samples were assayed for cellular fibronectin, vascular cell adhesion molecule-1, and intracellular adhesion molecule-1. Smoking status was determined by urinary cotinine concentrations.

RESULTS

Mean cellular fibronectin concentrations were different by time (P<.001) and smoking status (P=.01); the lowest concentrations were found in smokers. In contrast, intracellular adhesion molecule-1 was different by smoking status (P=.046); the highest concentrations were found in smokers. Vascular cell adhesion molecule-1 was different over time (P<.001), but not by smoking status.

CONCLUSION

Smoking during pregnancy is associated with reduced cellular fibronectin and increased intracellular adhesion molecule-1. These differences may be the result of different aspects of endothelial function or the source of the marker. The explanation for reduced preeclampsia in smokers remains elusive.

Origin of anti-tumor immunity failure in mammals and new possibility for immunotherapy

There is now much evidence that tumors can be immunogenic. Tumor cells very often express antigens in a form recognizable by the host immune system, but most frequently without consequences on tumor progression. This has been shown in many experimental models and different experimental conditions. Immediate mechanisms for the escape of tumors from immune response are very similar with mechanisms for the escape of fetoplacental unit (as an allograft) from maternal immune response. Similarity between these two mechanisms is so significant that any randomness is banished. Mechanisms of anti-tumor immunity in mammals are substantially different in comparison with mechanisms of anti-tumor immunity in other classes of vertebrates. Moreover, type of most frequently tumors in non-mammalians vertebrates is also significant different. Incidence of malignant tumors in non-mammalians vertebrates is significantly less than incidence of malignant tumors in mammals. These facts indicate that immune system of mammals during anti-tumor immune response is tricked with similarity between tumor cells and trophoblast or other placental cells. It may be a specific evolutionary approach in rendering of anti-tumor immunity failure in mammals, and new possibility for anti-tumor immunotherapy.

Expression of intercellular adhesion molecule-1 on the surface of peripheral blood and decidual lymphocytes of women with pregnancy-induced hypertension

OBJECTIVE

If overexpression of intercellular adhesion molecule-1 (CD54) on lymphocytes exists it could have important implications for the pathophysiology of pregnancy-induced hypertension (PIH).

STUDY DESIGN

CD54 "in vitro" expression (described as (%) of CD54+cells and CD54 mean fluorescence intensity, MFI) on the peripheral blood and decidual lymphocytes of pregnant with pre-eclampsia (PE) (n=16), transient hypertension (TH) (n=12), and controls (n=9).

RESULTS

The percent (%) of CD54+peripheral blood lymphocytes, CD54 MFI on them and CD54 MFI on decidual lymphocytes were increased especially in PE. During PE the (%) of CD54 decidual lymphocytes correlated negatively with platelet count. In TH the positive correlation between the blood pressure and the (%) of CD54 peripheral blood lymphocytes as well as CD54 MFI on decidual lymphocytes were found.

CONCLUSIONS

(1) PIH, especially PE, is accompanied by overexpression of intercellular adhesion molecule-1 (ICAM-1) on peripheral blood and decidual lymphocytes studied "in vitro", (2) Some of the parameters studied seem to correlate with clinical markers of PIH intensity but this fact needs further investigations using larger subject groups.

Novel chemiluminescence assay for serum periostin levels in women with preeclampsia and in normotensive pregnant women

OBJECTIVE

We recently developed a novel sandwich chemiluminescence assay to determine serum concentrations of periostin. Periostin has high amino acid homology with transforming growth factor-beta-induced protein beta igh3, a molecule induced by transforming growth factor-beta(1), which promotes the adhesion and spreading of fibroblasts. It is also homologous with the insect cell adhesion molecule fasciclin I. We determined serum periostin concentrations in women with preeclampsia and in normotensive pregnant women.

STUDY DESIGN

The study groups included 30 women with preeclampsia and 30 normotensive pregnant women at Magee-Womens Hospital. Blood samples collected from these women were assayed for periostin by use of newly developed monoclonal and polyclonal antibodies. We studied periostin messenger ribonucleic acid (mRNA) expression in human tissues by using reverse transcriptase-polymerase chain reaction and in situ hybridization.

RESULTS

Serum periostin concentrations were elevated in patients with preeclampsia (mean +/- SD, 311.8 +/- 56.3 ng/mL) compared with normotensive pregnant women (218.8 +/- 37.3 ng/mL). No correlation was found between serum concentrations of periostin and concentrations of TGF-beta(1), vascular cell adhesion molecule-1 (VCAM-1), E-selectin, and interleukin-6. Reverse transcriptase-polymerase chain reaction analysis demonstrated human periostin expression in lung, kidney, and placenta but not in the heart, liver, brain, or skeletal muscle. For periostin complementary deoxyribonucleic acid cloned from placenta, there was a splicing deletion within the C-terminal domain. In situ hybridization data showed that the periostin gene was expressed in the stroma cells of placenta.

CONCLUSION

Our study suggests that human periostin may play a role in the pathogenesis of preeclampsia. Although its function remains unclear, the expression of periostin as an adhesion molecule could suggest novel mechanisms in preeclampsia.

Activation of leukocytes during the uteroplacental passage in preeclampsia

Endothelial dysfunction and inflammation appear to play a major role in the pathogenesis of preeclampsia. We hypothesize that a chronic inflammation in the decidua and placenta during preeclampsia may lead to a local leukocyte activation in this compartment. Venous blood was sampled simultaneously from antecubital and uterine veins during cesarean sections in 30 women with preeclampsia, 29 with uncomplicated pregnancies, and from 17 nonpregnant women. The expression of adhesion molecules and complement-related markers on neutrophils and monocytes was analyzed by flow cytometry. In patients with preeclampsia, neutrophil expression of the integrins CD11a, CD11b, and CD11c and of the complement related markers CD35 and CD59 was significantly higher in samples from uterine than from antecubital veins. No differences were found in nonpregnant women. On monocytes the expression of the Sialyl Lewis(x) antigen, the integrins CD11a, CD11c, and CD49d, and the complement-related markers CD46 and CD59 was higher in samples from uterine than from antecubital veins during preeclampsia, but not in uncomplicated pregnancies, whereas in nonpregnant women CD31 was decreased. Our findings suggest activation of neutrophils and monocytes taking place during the uteroplacental passage in preeclamptic, but not in normal pregnancies. Such a local inflammatory response involving enhanced leukocyte/endothelial interaction may contribute to the pathogenesis of this disorder.

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.

The vitronectin receptor plays a role in the adhesion of human cytotrophoblast cells to endothelial cells

During placental development in higher primates trophoblast cells invade maternal blood vessels and migrate along the luminal surface of endothelium. In the present study, the adherence of human cytotrophoblast cells to endothelial cells has been characterized to test the hypothesis that vitronectin receptors (alpha(v) integrins) play a role in intra-luminal trophoblast migration. Adherence was measured using a quantitative fluorescence-based assay and was found to increase in a time-dependent fashion up to about 2 h after which it leveled off. Adhesion was detectable at 4 degrees C but was greatly reduced compared to that seen at 37 degrees C. Adhesion was partially blocked by antibodies against alpha(v)beta3/beta5 integrin, beta1 integrin and by antibodies against P-selectin. Antibodies against beta3 integrin subunits had no effect. Adhesion was reduced by galactose-6-phosphate and fructose-6-phosphate. Flow cytometric analysis revealed alpha(v) integrin on the surface of cytotrophoblast and endothelial cells. Beta1 integrin was detected on the surface of endothelial cells and on cytokine-stimulated cytotrophoblast cells. Beta3 and beta5 integrins were not detected on the surface of either cell type, although beta3 was detected using permeabilized endothelial cells. These results raise the possibility that alpha(v) integrins expressed by both cytotrophoblast cells and endothelial cells, and P-selectin expressed by endothelial cells, may be important in facilitating trophoblast adhesion and migration along the uterine microvasculature.

Immunology at the maternal-fetal interface: lessons for T cell tolerance and suppression

Mammalian reproduction poses an immunological paradox because fetal alloantigens encoded by genes inherited from the father should provoke responses by maternal T cells leading to fetal loss. Current understanding of T cell immunobiology and the critical role of inflammatory processes during pregnancy is reviewed and discussed. Lessons derived from studies on the regulation of T cell responsiveness during mammalian gestation are considered in the wider context of T cell tolerance toward some microbial infections and tumors, avoidance of autoimmunity, and tissue allograft rejection.

Early detection of preeclampsia by determination of platelet aggregability

Preeclampsia is still a leading cause of maternal and fetal morbidity and mortality. There is evidence for the involvement of platelets. Therefore, we investigated the suitability of corrected whole blood impedance aggregometry as an early predictor of preeclampsia in 71 consecutive, high-risk pregnancies. According to the occurrence of preeclampsia, defined postpartum by an independent investigator, and the stage of pregnancy (early and late, cutoff: 25 weeks of gestation), four study groups were defined. Platelet aggregation data were corrected for the influence of hematocrit and platelet count by a special purpose software package. Women developing preeclampsia showed significantly higher platelet aggregation response compared to controls in early and late pregnancy. In early pregnancy, all women developing preeclampsia had aggregation responses to collagen higher than the highest responses among the controls. Hence, this test had a 100% positive predictive value of subsequent preeclampsia. Despite being significantly increased, platelet aggregability was of minor predictive value in late pregnancy. We conclude that preeclampsia is accompanied by exaggerated platelet aggregability, particularly perceptible early in the course of pregnancy. We propose collagen-induced whole blood platelet aggregation with correction for the influence of hematocrit and platelet count for early detection of preeclampsia.

Normal expression of cell adhesion molecules in placentae from women with systemic lupus erythematosus and the antiphospholipid syndrome

Pregnant women with active systemic lupus erythematosus (SLE) and/or the antiphospholipid syndrome (APS) are prone to recurrent miscarriage, pre-eclampsia, intrauterine growth restriction and premature delivery. Placental dysfunction may account for these complications yet the mechanisms remain uncertain. Amongst these, an inflammatory response in the placental vasculature could play a role, involving recruitment of neutrophils and platelets and the increased endothelial expression of cell adhesion molecules (CAM), central to the recruitment process. The aim of this study was primarily to investigate CAM expression in the fetoplacental vasculature in women with SLE/APS. Circulating maternal concentrations of soluble CAM were also elucidated. There were no differences in CAM immunostaining in placentae from patients with SLE and/or APS compared with controls. In both patients and controls moderate immunostaining for the intercellular adhesion molecule-1 (ICAM-1) was observed in placental vascular endothelium and mild immunostaining was present in the placental villous stroma. Strong immunostaining for platelet endothelial CAM (PECAM) occured in the placental vascular endothelium whereas P-selectin was mildly expressed in the stem vessel endothelium only. Vascular CAM-1 (VCAM-1) and E-selectin were undetectable in either study or control placentae. In contrast, ICAM-1 and VCAM-1 but not E-selectin, as assessed by immunoassay (ELISA), were elevated in maternal serum from SLE/APS patients compared with controls. This study suggests that upregulation of CAM expression and subsequent activation of neutrophil and/or platelet activity within the placental villous tree is unlikely to be a mechanism by which the adverse pregnancy outcome arises in SLE/APS pregnancies. However, maternal endothelial cell activation (ECA) may play a more important role.

Altered circulating levels of adhesion molecules at 18 weeks' gestation among women with eventual preeclampsia: indicators of disturbed placentation in absence of evidence of endothelial dysfunction?

OBJECTIVE

The purpose of this study was to investigate whether indications of activation of the maternal endothelium were present at 18 weeks' gestation in women in whom preeclampsia eventually developed.

STUDY DESIGN

A total of 2190 blood samples were obtained at 18 weeks' gestation. Circulating levels of von Willebrand factor and soluble vascular adhesion molecule 1, soluble intercellular adhesion molecule 1, and E-selectin were assayed in 71 women with eventual preeclampsia and 71 control subjects.

RESULTS

E-selectin and von Willebrand factor levels were similar between the 2 groups. Soluble vascular adhesion molecule 1 concentration was significantly lower in the women with eventual preeclampsia (median, 649.0 ng/mL vs 762.4 ng/mL; P <.001), whereas soluble intercellular adhesion molecule 1 concentration was significantly higher (median, 239.8 ng/mL vs 178.3 ng/mL; P <.001).

CONCLUSION

We found no indications of endothelial activation at 18 weeks' gestation in women in whom preeclampsia later developed. However, decreased serum concentration of soluble vascular adhesion molecule 1 and increased serum concentration of soluble intercellular adhesion molecule 1 may reflect the disturbed placentation known to be associated with the development of preeclampsia.

Enhanced expression of intercellular adhesion molecule-1 (ICAM-1) in amnion with term and preterm labour

To evaluate the association between intercellular adhesion molecule-1 (ICAM-1) in the amnion and preterm labour and delivery, we have assessed ICAM-1 mRNA abundance by Northern analysis and protein levels by enzyme-linked immunosorbent assay (ELISA), in samples of this tissue after term and preterm delivery. The median ICAM-1 mRNA expression following preterm delivery (PTD, n=30) was 24 times greater (P< 0.05) than following elective caesarean section prior to labour at term (CST, n=14). ICAM-1 expression following vaginal delivery after spontaneous labour at term (SLT, n=11) was seven times greater than in the CST group (P< 0.05). The concentration of ICAM-1 protein in the PTD samples (n=31) was four-fold greater than (P< 0.05) in CST (n=14). It was also three-fold greater than in the SLT (n=15) samples (P< 0.05). The results were substantially the same when a preterm spontaneous labour group (PTL) (n=26), exclusive of deliveries complicated by pre-eclampsia (n=1) or intrauterine growth restriction (n=3), was compared to the CST and SLT groups. The ICAM-1 mRNA expression did not differ significantly (P=0.93) between PTL with (n=12) or without (n=14) indicators of intrauterine infection. The results were similar when ICAM-1 protein concentrations were compared (P=0.43) between these two groups. These findings indicate that ICAM-1 is expressed by the human amnion and that this expression is elevated with preterm labour and delivery.

A Deficiency of Placental IL-10 in Preeclampsia

Accommodation of the fetoplacental unit in human pregnancy requires maternal immune tolerance to this “semiallograft”. Local antiplacental immunity is modified by synthesis of uncommon histocompatibility Ags (e.g., HLA-G), growth factors, and cytokines by the placenta. Placental interleukins have been identified in reproductive tissues, but their roles in adaptive maternal immunity and determining term pregnancy outcomes have not been fully clarified. This study examined the distribution of IL-10 and TNF-α staining in term placentas. Women with proteinuric hypertension (PE, n = 10) were compared with an age-matched group with normal pregnancy (NP, n = 14) and gestational hypertension (GH, n = 6). Using immunohistochemistry of parrafin-fixed tissues, trophoblast cells were identified by cytokeratin 7 and cytokeratin 18 staining. The cytokine binding of villous trophoblast cells was scored depending on the extent of circumferential cytoplasm staining (&lt;25%; intermediate or &gt;75%). The cytokine positive decidual cells were scored as a percentage of total extravillous trophoblast cells. There was a reduction in villous IL-10 immunostaining compared with normal term placenta (PE, 10.2 ± 1.1, mean ± SEM; NP, 14.07 ± 1.16 Mann-Whitney U test; p = 0.02). In these patients, there was an increase in TNF-α immunostaining. Sparse endovascular extravillous trophoblast cells demonstrated nuclear IL-10 staining in 30% of patients with preeclampsia. Serum IL-10 was diminished in women with preeclampsia compared with normal pregnancy. In conclusion, villous trophoblast demonstrated diminished immunostaining of IL-10 in preeclampsia. This abnormality may be associated with heightened maternal antifetal immunity and therefore inadequate placental development in preeclampsia.

A selective increase in plasma soluble vascular cell adhesion molecule-1 levels in preeclampsia

PROBLEM

The study was conducted to determine whether altered plasma levels of soluble intercellular adhesion molecule (ICAM)-1 and soluble vascular cell adhesion molecule (VCAM)-1 are involved in the pathogenesis of preeclampsia.

METHOD OF STUDY

Maternal plasma samples were collected from 20 patients with preeclampsia, 20 matched normotensive patients with uncomplicated pregnancies. and ten healthy nonpregnant women. Samples were assayed for soluble VCAM-1 and soluble ICAM-1 by specific enzyme-linked immunosorbent assay.

RESULTS

Both soluble VCAM-1 and soluble ICAM-1 were detectable in the plasma of all preeclamptic, normotensive pregnant, and nonpregnant women. The mean plasma level of soluble VCAM-1 was significantly higher in preeclamptic women compared to normotensive pregnant women (1831 ng/mL +/- 534 ng/mL vs. 1254 ng/mL +/- 386 ng/mL, respectively; P < 0.05). However, the plasma level of soluble VCAM-1 was unchanged during the third-trimester of normal pregnancy compared to nonpregnant women. The mean plasma level of soluble ICAM-1 in preeclamptic and normotensive pregnant women were increased when compared to nonpregnant women. However, the mean plasma level of soluble ICAM-1 was comparable in women with preeclampsia and normotensive pregnancy.

CONCLUSIONS

The selective increased plasma levels of soluble VCAM-1 in patients with preeclampsia provide evidence for endothelial activation and suggest distinct pathways for neutrophil and endothelial activation in preeclampsia.

Adverse pregnancy outcome in the antiphospholipid syndrome: focus for future research

Pregnant patients with antiphospholipid syndrome (APS) may suffer from recurrent pregnancy loss, pre-eclampsia, intrauterine growth restriction and placental abruption. These conditions inevitably result in a high incidence of premature delivery with all the neonatal complications that follow. The mechanism underlying these adverse pregnancy outcomes has not yet been established. This may be primarily a maternal disease process with secondary placental maldevelopment and/or malfunction. Alternatively, there may be primary placental damage mediated directly or indirectly by antiphospholipid antibodies. The safe and successful treatment of pregnant women with APS lies in the understanding of the aetiology of this condition and the mechanism by which complications in pregnancy may arise. In this article we highlight areas in which research may be targeted such that our understanding of the pathogenesis of adverse pregnancy outcome may be enhanced.

Review: immunobiology of preeclampsia

Preeclampsia has been recognized clinically since the time of Hippocrates: however its etiology and pathophysiology remain enigmatic. This pregnancy-specific syndrome typically presents in late pregnancy as hypertension, edema, and proteinuria. Investigations over the past 15 years have revealed that preeclampsia is associated with abnormal placentation, reduced placental perfusion, endothelial cell dysfunction, and systemic vasospasm. Since it occurs more commonly in primigravidae and in women with underlying collagen-vascular diseases, an immunological component has long been suspected. Increased prevalence in high-order and molar pregnancies and those associated with increased placental mass suggests that trophoblastic volume and fetal antigen load are correlated with the syndrome. Epidemiological reports indicate that the prevalence of preeclampsia is decreased in women who received heterologous blood transfusions, practiced oral sex, or when a long period of cohabitation preceded an established pregnancy. Conversely, the use of condoms as a primary mode of contraception is associated with a higher risk of preeclampsia. These studies suggest that prior exposure to foreign or paternal antigens imparts a protection against the likelihood of developing preeclampsia. Clinical evidence of cellular and humoral immune dysfunction is associated with the syndrome. Fibrin and complement deposition and "foam" cells in atherosis lesions resemble the histopathology of renal allograft rejection. Relative T-cell, natural killer cell, and neutrophil activation have been reported in preeclampsia and circulating cytokines and antiphospholipid antibodies are more prevalent in preeclampsia than in normal pregnant women. These abnormalities are consistent with the systemic endothelial cell dysfunction that has been postulated as a pathophysiological feature of preeclampsia. While such associations do not prove causality, they suggest testable hypotheses for continued basic and clinical investigation of this major complication of human pregnancy.

Macaque intra-arterial trophoblast and extravillous trophoblast of the cell columns and cytotrophoblastic shell express neural cell adhesion molecule (NCAM)

BACKGROUND

During placental development in higher primates trophoblast cells originating in the cell columns migrate along endometrial surfaces to form the cytotrophoblastic shell. A subpopulation of these cells invades uterine arteries, where they migrate on the surface of endothelium, against the flow of blood. These intra-arterial cells become sequestered in the walls of the arteries where they are referred to as intramural trophoblast. Because migration depends upon binding the cell surface to other cells or to extracellular matrix, we investigated the potential role of neural cell adhesion molecule (NCAM, CD56) in arterial invasion by trophoblast cells.

METHODS

Tissues from macaque placentas and endometrium were fixed and embedded in paraffin. Standard immunoperoxidase methods were used to identify NCAM.

RESULTS

NCAM labeled cells were present within spiral arteries of the decidua basalis. Trophoblast cells within or adjacent to the arterial lumen were distinctly NCAM positive, whereas most intramural trophoblast cells revealed reduced or no reactivity for NCAM. Maternal endothelial cells and villous trophoblast cells were negative. Uterine veins were tapped by trophoblast but did not contain migratory cells. The cell columns of early pregnancy contained cells outlined by rims of reactivity for NCAM. Labeled cells were also seen in the cytotrophoblastic shell, arranged as discontinuous groups. These groups variably occupied the entire thickness of the shell, or only the proximal (adjacent to the intervillous space) or distal layers of the shell. Later in gestation, the cytotrophoblastic shell developed a different pattern of staining, such that only cells located nearer to the intervillous space or near the tips of the anchoring villi were positive.

CONCLUSIONS

We conclude that NCAM is one of a group of cell adhesion molecules that participates in trophoblast cell adhesion during migration within maternal arteries. NCAM appears to be active in trophoblast-trophoblast cell interactions. It may also contribute to binding trophoblast cells to the surfaces of arterial endothelium as well as extracellular matrix molecules of the arterial wall. After secondary invasion into the arterial walls NCAM is down-regulated, possibly in response to the appearance of extracellular matrix capsules, where other cell adhesion molecules may appear.