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

Circulating Inflammatory Cytokines and Female Reproductive Diseases: A Mendelian Randomization Analysis

CONTEXT

Extensive studies have provided considerable evidence suggesting the role of inflammation in the development of female reproductive diseases. However, causality has not been established.

OBJECTIVE

To explore whether genetically determined circulating levels of cytokines are causally associated with female reproductive diseases and discover potential novel drug targets for these diseases.

METHODS

Instrumental variables (IVs) for 47 circulating cytokines were obtained from a genome-wide association study (GWAS) meta-analysis of 31 112 European individuals. Protein quantitative trait loci and expression quantitative trait loci close to genes served as our IVs. Summary data of 9 female reproductive diseases were mainly derived from GWAS meta-analysis of the UK biobank and FinnGen. We elevated the association using the Wald ratio or inverse variance-weighted Mendelian randomization (MR) with subsequent assessments for MR assumptions in several sensitivity and colocalization analyses. We consider a false discovery rate <0.05 as statistical significance in MR analyses. Replication studies were conducted for further validation, and phenome-wide association studies were designed to explore potential side effects.

RESULTS

Our results indicated that high levels of macrophage colony-stimulating factor (MCSF), growth-regulated oncogene-alpha (GROα), and soluble intercellular adhesion molecule-1 were associated with increased risks of endometriosis, female infertility, and pre-eclampsia, respectively. High platelet-derived growth factor-BB (PDGF-BB) levels that reduced the risk of ovarian aging were also supported. Replication analysis supported the relationship between GROα and female infertility, and between MCSF and endometriosis.

CONCLUSION

We identified 4 correlated pairs that implied potential protein drug targets. Notably, we preferred highlighting the value of PDGF-BB as a drug target for ovarian aging, and MCSF as a drug target for endometriosis.

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.

Plasma Factors in Severe Early-Onset Preeclampsia Do Not Substantially Alter Endothelial Gene Expression In Vitro

OBJECTIVE

Systemic endothelial dysfunction is a central feature in the pathophysiology of preeclampsia. Its cell biologic and molecular basis is poorly understood. One leading hypothesis argues that endothelial dysfunction is caused by (at present largely unknown) circulating factors released from the ischemic placenta. This study investigated the effects of plasma factors of severe, early-onset preeclamptic women versus healthy pregnant women on endothelial gene expression in vitro.

METHODS

Plasma samples were taken from eight severe early-onset preeclamptic women and eight matched pregnant control women. Primary human umbilical vein endothelial cell (HUVEC) and human glomerular microvascular endothelial cell (hGMEC) cultures were incubated with 20% (vol/vol) plasma for 4, 12, and 24 hours. Identical amounts of RNA isolated from HUVEC from three preeclamptic and three control samples were pooled for each time point, and subsequently hybridized on human 60-mer oligonucleotide microarrays containing 17,000 genes. Gene expression levels of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), interleukin-8 (IL-8), and interleukin-6 (IL-6) in HUVEC and hGMEC were quantified using real-time reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

Microarray analyses of individual genes identified no genes that were up- or down-regulated more than 2.7-fold, and analyses of gene ontologies showed no gene ontology significantly up- or down-regulated in HUVEC by preeclamptic plasma. IL-8 gene expression was modestly induced by preeclamptic plasma after 4, 12, and 24 hours of HUVEC and hGMEC incubation, as identified by real-time RT-PCR. The other genes analyzed did not show altered regulation by preeclamptic plasma factors.

CONCLUSIONS

In vitro, plasma from preeclamptic patients does not substantially alter endothelial gene expression profile. Only modest induction of IL-8 gene expression was observed. These results indicate that mechanisms other than soluble plasma constituents are likely involved in systemic endothelial cell activation in preeclampsia.

TNF α G308A gene polymorphism has an impact on renal function, microvascular permeability, organ involvement and severity of preeclampsia

BACKGROUND/AIMS

Preeclampsia (PE) is a life-threatening complication of pregnancy that is associated with a high rate of maternal and perinatal morbidity and/or mortality worldwide. If untreated, it can progress to eclampsia, which can result in the death of the mother, the fetus or both. The etiology of PE is still uncertain; however, recently the role of the immune system has gained in importance. The role of tumor necrosis factor-α (TNF-α), a cytokine involved in inflammation processes, has been widely investigated in obstetric disorders. The aims of the present study were to investigate the effect of TNF-α gene G308A (rs1800629) polymorphism on disease risk, renal function, microvascular permeability, endothelial cell dysfunction and organ involvement in women with PE.

METHODS

Initially, 102 3rd-trimester pregnant women (preeclamptic cases and healthy controls) with singleton pregnancy were invited for participation, of which 76 were genotyped for TNF-α G308A polymorphism and evaluated for plasma levels of soluble vascular cell adhesion molecule-1 (sVCAM-1), fibronectin and TNF-α, which were tested for correlations with the profile of PE. The odds ratio (OR) and 95% confidence intervals obtained from unconditional logistic regression were used to test the association between the TNF-α polymorphism and PE risk. For continuous variables, we applied Student's t test and, for categorical variables, the Pearson χ(2) or Fisher's exact test. The two-way ANOVA test with Bonferroni correction was used in multivariate analyses.

RESULTS

The A allele was more frequent in cases than controls (22.4 vs. 13.2%), which increased disease risk (OR = 2.73). Maternal serum levels of TNF-α, sVCAM-1 and fibronectin were significantly increased in cases (855.8 ± 385.1 pg/ml, 1,243 ± 671 ng/ml, 0.308 ± 0.231 g/l, respectively) compared to controls (301.1 ± 156.1 pg/ml, 651 ± 250 ng/ml, 0.218 ± 0.101 g/l, respectively; p < 0.0001, p < 0.0001 and p = 0.031, respectively), and these levels showed an increasing trend with the mutant allele genotype. Moderate and severe proteinuria was higher in rs1800629 allele A subjects compared to G/G carriers (53.8 vs. 14.3% (p < 0.05) and 13.0 vs. 4.7% (p < 0.01), respectively). The adverse effect of rs1800629 allele A on renal function was confirmed by increased plasma creatine levels, urinary protein excretion and lower tubular resorption rate in preeclamptic patients. Moreover, rs1800629 allele A preeclamptic carriers showed higher serum levels of fibronectin and sVCAM-1 compared to G/G homozygotes.

CONCLUSION

This study reveals a possible association between clinical and laboratory manifestations of PE and the TNF-α gene G308A (rs1800629) polymorphism.

Activation of NF-κB in placentas of women with preeclampsia

OBJECTIVE

Placentas are oxidatively stressed during preeclampsia and produce more tumor necrosis factor α (TNFα) and more thromboxane than normal. Oxidative stress may cause these abnormalities by activating nuclear factor-κB (NF-κB). We measured the levels of activated NF-κB in normal and preeclamptic placentas and determined whether oxidative stress activates NF-κB in a trophoblast-like cell line.

METHODS

We used immunohistochemistry to determine the percentage of the total tissue area that stained for the p65 subunit of NF-κB in placentas obtained from normal and preeclamptic pregnancies. In a second set of experiments, we used a reporter plasmid bearing the NF-κB binding site and transfected it into trophoblast-like cells. The cells were incubated with medium control, linoleic acid (LA), an oxidizing solution (Ox), or Ox enriched with LA (OxLA), TNFα, or OxLA plus TNFα for 20 h. Cell lysates were analyzed using a dual luciferase assay kit.

RESULTS

Placentas obtained from women with preeclampsia showed nearly a 10-fold increase in the extent of area stained for activated NF-κB as compared to normal placentas. In cell culture experiments, Ox and OxLA induced a threefold increase in NF-κB activation as compared to medium control or LA. TNFα induced a threefold increase in NF-κB activation. The combination of TNFα with OxLA caused a 10-fold increase in NF-κB activation.

CONCLUSIONS

Placental NF-κB is activated nearly 10-fold in preeclampsia. Oxidative stress causes NF-κB activation in a trophoblast-like cell line, which is enhanced by TNFα. These data suggest that oxidative stress is likely an important in vivo activator of placental NF-κB in preeclampsia.

Markers for Presymptomatic Prediction of Preeclampsia and Intrauterine Growth Restriction

Preeclampsia and intrauterine growth restriction are both characterized by placental malfunction. The pathological processes of abnormal trophoblast invasion, partial absence of maternal spiral artery modification, increased apoptosis of trophoblast cells, and placental ischemia are all associated with the release of specific molecules. These proteins, as well as cell-free fetal DNA and RNA might be detected in the maternal peripheral circulation, quantified, and used for early identification and prediction of preeclampsia and intrauterine growth restriction, prior to the appearance of the clinical symptoms. As preeclampsia and intrauterine growth restriction are associated with increased maternal, perinatal, and neonatal morbidity and mortality, early identification of these pregnancy associated complications will permit the design of appropriate preventive measures. In this review a variety of factors reported to be useful as potential markers for early detection of pregnancies at increased risk will be discussed. Molecules associated with the establishment of the placenta and essential in fetal-maternal interactions, like interleukin 2-receptor, insulinlike growth factor-1, and insulinlike growth factor binding protein-1, placenta growth factor, hepatocyte growth factor, inhibin A, activin A, and human chorionic gonadotrophin seem to be the most likely candidates for presymptomatic markers for preeclampsia and/or intrauterine growth restriction. Detection and discrimination of these molecules through the placental RNA in maternal plasma based strategy has become a realistic option.

Nocturnal hypertension is associated with an exacerbation of the endothelial damage in preeclampsia

BACKGROUND

Non-dipping pattern of circadian blood pressure in preeclampsia is associated with an increased risk of cardiovascular disease. The pathogenetic mechanisms of this relationship are still unclear. We investigated whether non-dipping in preeclampsia could relate to endothelial activation or damage.

METHODS

Participants, 20 women with normal pregnancy (mean age 29.9 +/- 5.7 years) and 31 women with preeclampsia (mean age 29.1 +/- 5.1 years), underwent 24-hour ambulatory blood pressure monitoring. Plasma levels of von Willebrand factor (vWf), marker of endothelial damage and of soluble adhesion molecules (sVCAM-1, sICAM-1), and markers of endothelial activation were determined using commercially available enzyme-linked immunoassays.

RESULTS

Based on whether the nocturnal mean arterial pressure (MAP) relative to the daytime MAP declined by less than 10%, 21 women with preeclampsia were categorized as non-dippers. Compared to healthy pregnant women, patients with preeclampsia showed significantly enhanced levels of vWf (206.9 +/- 40.6 vs. 123 +/- 24 IU/dl;p<0.01) and sVCAM-1 (2,269 +/- 426 vs.1,159.8 +/- 340 ng/ml; p < 0.01). In addition, significantly higher levels of vWf (224.5 +/- 34.9 vs. 170 +/- 23 IU/dl; p < 0.01) and sVCAM-1 (2,405 +/- 421.4 vs. 1,983 +/- 276.7 ng/ml; p = 0.007) were determined, when women with preeclampsia and nocturnal hypertension (non-dippers) were compared to dippers. The results were similar even after adjustment for severity of preeclampsia. In contrast, neither preeclampsia nor dipping status had an effect on sICAM-1 levels.

CONCLUSION

Nocturnal hypertension in preeclampsia is associated with elevated levels of molecules related to endothelial damage. Endothelial damage is a recognized pathogenetic factor for atherosclerosis and history of preeclampsia is a risk factor for cardiovascular disease. In this context, possible clinical implications of our findings deserve further investigation.

Adhesion molecules changes at 20 gestation weeks in pregnancies complicated by preeclampsia

OBJECTIVES

To examine soluble E-selectin, L-selectin, P-selectin, ICAM-1, and VCAM-1 levels in normotensive and preeclamptic pregnancies. To determine cut-offs useful for preeclampsia early detection.

STUDY DESIGN

A cohort of nulliparous women was recruited at family medicine clinics in Mexico City. Preeclampsia developed in 75 patients; 125 normotensive controls were matched. Adhesion molecules were assessed in serum obtained at 20 gestation weeks and in third trimester pregnancies. Predictive values and odds ratios for preeclampsia development were calculated with the 20 gestation week results. Threshold values were selected based on ROC curves values.

RESULTS

In women with subsequent preeclampsia, sL-selectin and sVCAM-1 concentrations were significantly lower, whereas sE-selectin, sP-selectin and sICAM-1 levels were significantly higher, compared with controls at mid-pregnancy (p<0.05). The odds ratio for low sL-selectin was 25.6 (95% CI, 8.9-73.5; cut-off, 1414 ng/ml). The sensitivity, specificity, and positive and negative predictive values of low sL-selectin for preeclampsia development were 84, 90, 39, and 98%, respectively, whereas its sensitivity, specificity, and positive and negative predictive values for severe preeclampsia development (cut-off, 1210 ng/ml) were 100, 98, 60, and 100%, respectively.

CONCLUSIONS

Early enhanced activation of endothelial cells, platelets and leukocytes seem to be present in preeclamptic patients, especially in those that develop severe preeclampsia. Low sL-selectin levels at 20 gestation weeks may be an indicator of preeclampsia development.

Increased Intima-Media Thickness After Early-Onset Preeclampsia

OBJECTIVE

Preeclampsia is associated with cardiovascular atherosclerotic events later in life. However, little is known about earlier subclinical signs of atherosclerosis. We aimed to investigate whether women who recently had preeclampsia show increased intima-media thickness (IMT), as marker of early atherosclerosis, compared with women with normal pregnancies or nulliparous women.

METHODS

Intima-media thickness of carotid and femoral arteries measured by ultrasonography, and possible confounding risk factors as body mass index, blood pressure, serum lipids, smoking status, and family history of cardiovascular disease were compared among 22 nulliparous women, 22 primiparous women with normal pregnancy, and 22 primiparous women with early-onset preeclampsia at least 3 months postpartum and 6 weeks after ending lactation

RESULTS

Except for slightly higher values for blood pressure, triglycerides, and homocysteine in the formerly preeclamptic women, no other clinical or biochemical differences were observed. The preeclampsia group showed an increased IMT (mean +/- standard deviation, 0.63 +/- 0.14 mm) of the common femoral artery compared with the normal pregnancy group (0.55 +/- 0.06 mm, P = .005) and to the nulliparous group (0.52 +/- 0.06 mm, P < .001). These differences remained significant after correction for possible confounders by multiple linear regression analyses. An increase in IMT of the common carotid artery between the normal pregnancy and the nulliparous group was observed, which became significant after adjustment for confounders.

CONCLUSION

Preeclampsia and, to a lesser degree, normal pregnancy are associated with increased IMT. The association between increased IMT and (preeclamptic) pregnancy leads to the question of which comes first, which should be addressed in follow-up studies.

LEVEL OF EVIDENCE

II-2.

Abnormal Endothelium-Dependent Microvascular Reactivity in Recently Preeclamptic Women

OBJECTIVE

To assess endothelial function at the level of skin microvasculature, using iontophoretic administration of acetylcholine (endothelium-dependent vasodilator) and sodium nitroprusside (endothelium-independent vasodilator), in women who recently had a preeclamptic pregnancy.

METHODS

Microvascular skin reactivity was assessed by laser Doppler perfusion monitoring and iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) in 25 women with a history of early onset preeclampsia and 23 women with previous uncomplicated pregnancies, all of whom were between 3 and 11 months postpartum.

RESULTS

Mean (+/- standard error of the mean) ACh-mediated vasodilatation, expressed as a percentage increase in flux, was higher in women who recently had a preeclampsia than in controls (535 +/- 46% versus 314 +/- 29%, P < .001). In contrast, SNP-mediated vasodilatation was not significantly different (560 +/- 71% versus 483 +/- 69%, P = .4) in both groups. Linear regression analysis revealed that the difference in ACh-mediated vasodilatation was explained by preeclampsia (P = .004), whereas vascular risk factors such as maternal age, diastolic blood pressure, and family history of premature cardiovascular diseases had no significant effect.

CONCLUSION

The increased ACh-mediated vasodilatation in the microcirculation of recently preeclamptic women indicates abnormal endothelial function. Furthermore, it may represent a compensatory response to an impaired vasodilatory response of the macrocirculation, thereby supporting the hypothesis of an underlying (micro)angiopathy.

Prediction of preeclampsia: can it be achieved?

In this review, the various biochemical tests that have been proposed for the prediction of preeclampsia are described and evaluated. Placenta hormone markers do not predict future disease. They denounce the early placental changes that are part of the evolving disease and only predict the imminent of preeclamptic syndrome. This explains why tests are better predictors when preeclampsia supervenes shortly, and why screening in the first trimester is unlikely to work as well as in the second trimester. The use of multiple markers in the screening should reflect different aspects of the disease process and could increase the specificity and sensitivity of the screening and work on different etiologic factors. The possible use of second-trimester biochemical screening to predict the risk of preeclampsia remains to be investigated in the high-risk population.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians

LEARNING OBJECTIVES

After completion of this article, the reader should be able to list the various theories on the etiology of preeclampsia, to relate the various risk factors for the development of preeclampsia, and to describe the various screening tests for preeclampsia.

Maternal serum levels of VCAM-1, ICAM-1 and E-selectin in preeclampsia

Endothelial dysfunction is thought to be a central pathogenic feature in preeclampsia on the basis of elevated adhesion molecules. The aim of the present study was to compare the levels of soluble vascular cell adhesion molecule-1 (sVCAM-1), intercellular adhesion molecule-1 (sICAM-1) and E-selectin (sE-selectin) in sera of normal and preeclamptic pregnancies. We studied the serum levels of sVCAM-1, sICAM-1 and sE-selectin in normal pregnant women (n=63), mild preeclampsia (n=33) and severe preeclampsia (n=82). Concentrations of soluble adhesion molecules were determined with enzyme-linked immunoassay (ELISA). Serum concentrations of sVCAM-1 were significantly higher in both mild (p=0.004) and severe preeclampsia (p=0.000) than normal pregnancy. There were also significant differences in sVCAM- 1 levels between mild and severe preeclampsia (p=0.002). sICAM-1 levels of severe preeclampsia were statistically different from those of normal pregnancy (p=0.038). Levels of sE-selectin were elevated in both mild (p=0.011) and severe preeclampsia (p=0.000) compared to normal pregnancy, but no statistical difference between the mild and severe preeclampsia (p=0.345). These results suggest that all three soluble adhesion molecules are increased in severe preeclampsia, and sVCAM-1 among them may be useful in predicting the severity of preeclampsia.

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.

Maternal endothelial soluble cell adhesion molecules with isolated small for gestational age fetuses: comparison with pre-eclampsia

OBJECTIVE

1. To evaluate the activation profile of the endothelium in pregnancies complicated by small for gestational age fetuses compared with pre-eclampsia and normal pregnancy, by measuring the plasma levels of soluble adhesion molecules soluble E-selectin, intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1. 2. To determine whether soluble adhesion molecules were related to the severity of small for gestational age fetuses and pre-eclampsia.

DESIGN

Observational study.

PARTICIPANTS

Sixteen women with small for gestational age fetuses; 15 women with pre-eclampsia and 15 healthy primigravidae were recruited as controls.

METHODS

Plasma levels of soluble E-selectin, intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1 were measured by ELISA.

RESULTS

Compared with the healthy controls, soluble E-selectin was significantly increased in both small for gestational age fetuses and pre-eclampsia, whereas intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1 were increased only in pre-eclampsia. In the small for gestational age fetuses group, soluble E-selectin correlated inversely with the ratio between birthweight and the expected normal birthweight (r = -0.4, P = 0.007). In the pre-eclampsia group, a significant correlation was observed between vascular cell adhesion molecule-1 and blood pressure (r = 0.54, P = 0.039).

CONCLUSIONS

Endothelial activation, reflected by raised levels of soluble E-selectin, is a feature of small for gestational age fetuses and is correlated with the severity of the disease. Differences in the profile of soluble cell adhesion molecules suggest variations in the degrees of endothelial activation between pre-eclampsia and small for gestational age fetuses.